We Keep Coding

Plug-in com.android.ide.eclipse.adt was unable to load class android

I am new to android development
My eclipse was working properly. But now when I start a new project it give an error
Problem opening wizard
The selected wizard could not be opened
The Detailed error message is
The selected wizard could not be started.
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectWizard.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (239).
I can't run existing Android project also.But I can start a new java project and run.
Why this is happening

If you have not added ADT then do the Following steps.
Help -> Add New Software -> Add.
In Name option write ADT
And if you have installed ADT in your Computer then add its path in Location like
jar:file:/D:/ADT-16.0.1.zip!/
And then ADT will install.
And if there is a problem try to remove that adt and install again.
1) remove the ADT repo (Window->Preferences->Install/Updates->Available Software Sites)
2) add Indigo repo ("http://download.eclipse.org/releases/indigo")
3) run updates
4) add ADT repo again and install

For me,what seemed to work was:
1.Restarting the application
2.(Or) Restarting the computer
I still had some problems.Some projects dint load.I'm not sure what the problem is or was.I think reinstalling ADT should do the trick.

Actually it is not necessary to uninstall the ADT plugin. Just add this repo(http://download.eclipse.org/releases/indigo) and then help->check for updates

I have been having a similar problem, and it seems to be the org.eclipse.objectteams plugin causing the trouble for me. What I needed to do was remove the plugin from my Eclipse plugin directory as follows:
mv ~/.eclipse/*/plugins/org.eclipse.objectteams* ~/someDIR
There seems to be dependency issues with the newer versions of Eclipse. Sorry if I can't provide more information.
Maybe see https://bugs.eclipse.org/bugs/show_bug.cgi?id=350133.

You will also get this fault if you have an AVD running. Close the AVD and restart eclipse

Am posting this answer for the people who is referring this post in future.
The methods that all mentioned will take more time. I have figured out this problem by updating plugin.
But it is not like the way as vic12 is mentioned. I have done this in the following way
Help > Install new software > click on link What is already installed you can see a list of installed software. You can choose and update any one as you want. If you click check for update it will update all the software that we installed it will take a lot of time. By this way you can update the one that you want. This can be done in a minute. it saves time.

In my case computer restart resolved all the issues without re-installing ADT plugin.
BTW, I am using MAC + ADT_v22

Go to Help - eclipse market place - search for adt. Then update or install it. This worked for me.

I had same problem and I have started to read answers above. then I stopped to read and just restarted eclipse and it is worked for me! (this is my first solution for all electronic devices and generally works :)

This can occur if you remove Android from your build path. Just try to relink JRE6 or 7 and restart the program. Eclipse will handle it for you.

I got this problem solved when I restarted Eclipse and changed the workspace am working on.

You can try changing the workspace too. It worked for me!

If you are on a Mac and user Eclipse ADT, go to ADT -> Preferences -> Android. There you should find an option for setting your Android SDK location. Simply browse for the existing ADT, and select the SDK folder.
This of course can only be done after the SDK has been installed.

Just restart the eclipse. It seems eclipse is having some bug which is leading other components from proper loading. Or first of all start sdk manager from background and then eclipse.

Simple:
This is work for me. Please follow these steps.
GO To:
Help>>Install New Software>>Available Software Sites
then Locate for:
http://download.eclipse.org/releases/indigo
If available then just select and reload
Else
ADD >> Location past this url in
http://download.eclipse.org/releases/indigo ">>OK Then >> Reload
Hope this help somebody .

Enter the variable 'PATH' the path of the JRE folder (java).

I hope that would help somebody:
I had the same problem and ironically the problem was in a simple code error. For some reason this error caused Eclipse to overreact with red lines all across the code and saving errors as well as the error mentioned in this post.
I fixed the problem (deleting an extra }) and all problems disappeared.
I don't know why Eclipse overreacted this time, but it's another option to check before you install, uninstall or update anything.
Good luck.

I just want to add this in here as the problem just occured with me. What I did was close eclipse, reopen it and then it started working. If this doesn't fix the issue then I advise you go with #Bhavin's answer.

You might have stored two ADT plugins one with link and other with zip file you have to delete one of them
Help -> Install new software -> Available software for sites -> and remove one of adt plugins.

How to avoid "Refreshing external Folders" in Android development in Eclipse

I am having this annoying problem which takes 10-20 seconds and sometimes more every time my android project is refreshed or rebuilt.
I searched for android forums and also in stackoverflow and but solutions does not make sense. Please give me the solution or link to it.
My android project depends on two external java libs and android libs. Tell me if you need more info.
Earlier I asked this question and it solved the problem by removing 'source attachment'. But I believe it is not a good solution because I need source to be attached with jar. It helps while debugging, code browsing. If source is not attached then, your breakpoint stops there and you can't go in readable source.
Better Solution Needed. Is there a launcher option? which disables when app launched. or build options?

Instead of attaching a source folder to the .jar file, you should zip the source folder and attach the zipped file to the .jar.
See this answer for more info https://stackoverflow.com/a/9699242/637754

The reason for this is that you have attached source with your dependent jars. Just the remove the source from the class path. This how it can be done.
Right click on the project -> Select Build Path -> Configure Build Path.. -> Select Libraries
Select the Source attachment and Remove button will highlight. Press Remove and OK.
I think that should fix your issue.

this helped me so you can try too:
Go to your Workspace root/.metadata/.plugins/org.eclipse.jdt.core/ and remove .org.eclipse.jdt.core.external.folders folder
it contains .project file with links to external folders which takes too long to refresh

You can disable "Refresh on access" option in Window->Preferences->General->Workspace - it have no effect as I think, because even it's turned on you must manually refresh projects if you modify them outside of Eclipse

If anything else fails (my case), install a fresh copy of Eclipse Juno
Go to Help-Install Software, and add this repo:
https://dl-ssl.google.com/android/eclipse/
Check all options and install.
For migration reasons I was trying to install Eclipse on MAC OS Yosemite, since Android Studio is now the official IDE, it is hard to find Eclipse setups with the ADT plugin included. I tried several versions of Eclipse, and JUNO did the work.

Error launching first test application: Android Packaging Problem?

Conversion to Dalvik format failed: Unable to execute dex:
wrapper was not properly loaded first
[project]
Android Packaging Problem
I've never worked with Java or eclipse before, I'm following this introductory guide and all searches via google return no helpful results. I'm guessing the problem is I have built Android stuff with eclipse properly but I have no idea, I followed this guide to the letter and everything went as it explains it should.
Any ideas what caused this problem, or is it specific to the guide? If so I'll post on their help page.
I have tried doing project -> source -> clean up, but that didn't fix anything.
Edit:
I went to Project -> Android tools -> Dex bytecode and it reported:
DexDump: missing classex.dex for project. Please compile first.
So I guess that's my problem! Not sure how to solve though.

Go to Project -> Clean
It will rebuilt workspace and fix the errors if any.

As I said, I had the same problem so I tried all the different versions and
then I stopped filling in the SDK-version number
and finally it did not complain anymore about the wrapper.
After that it was totally fine to write the SDK-version when I created new projects.
Hope it works out for you too.

Had the same problem (running on Windows 7). I resolved it by running Eclipse with Administrator privileges.

try to run eclipse under administrator permission. Problem may be resolve.
I think you installed the SDK in "Program Files" folder . So for do something inside, must have administrator permission.

One thing that may help is to create a new test Android project.
In Eclipse, select File → New → Android Project.
Set the project name to "Test3", check Android 2.3 for the build target, type "com.example.android.apps.test3" for the package name, and type "Test3Activity" in the "Create Activity:" text box. The form should look like:
Click Finish.
Expand the entry for "Test3" in the Package Explorer. Navigate to res/values/strings.xml. Double click on the entry for strings.xml:
Set the text content of the string element having name "app_name" to "Test3":
Right click on "Test3" in the Package Explorer and select Run As → Android Application. The emulator should open and after a long while, you should see:
If these steps do not work, then you probably have an error in your installation.
Try it out and let me know.

I had the same problem earlier today. Google was largely unhelpful.
I fixed it by removing the project from eclipse, then re-importing it.
According to this bug report the problem is caused by upgrading to version 9 of the SDK.

Had the same HelloWorld problem with Ubuntu 64 Lucid / Eclipse 3.5.2 from Ubuntu repository. Restarting Eclipse did the trick, though I notice it still fusses about API level requirement when HelloWorld is run.

Running it as Administrator has solved this issue for me..

Had the same problem - occurred after I tried downloading Android platform v2.3.3 (was using 3.1 and 3.2 earlier) and it interrupted in the middle - restarted eclipse and cleaned all projects and rebuilt and the problem went away

At what point in this tutorial/guide are you running into this problem and did you make sure to include your package information in each file or ie com.something.somethingelse at the top of your class or classes?
Perhaps a registry error or maybe even a problem with activity implementation.
Please post your code if this did not start you in the right direction.

Here are a few things to check:
Make sure you have the latest version oF Eclipse (Helios)
Make sure that you have the Android SDK plug-in for Eclipse.
Now if you have done that... Make sure that any classes you add (Each screen you view on Android is a class and is called an Activity) are in your androidmanifext.xml file See http://wrenbjor.com/2011/01/12/the-androidmanifest-xml-file/ for help on understanding this process.
otherwise make sure there are no red x's in your code or it wont work.
If you still have problems post some code and we can try to help.

Had the exact same problem the other night. Upgraded to Helios (3.6) and it went away, quite possibly as a side-effect.

Under windows 7, rather than run eclipse as an admin, change the permissions on the eclipse folder so the creator/owner has full control, and do the same with the folder the android SDK is installed into.

I had installed Eclipse using the files provided by Windows' native ZIP extractor. I deleted the files and took them from 7-Zip instead. Now the error is gone. So maybe using another ZIP extraction tool will help.

Recently got this when failing upgrade using adb-manager with eclipse open (win32). As eclipse was open, upgrade failed. Then returning to my project this problem occured.
Was solved by closing eclipse, restart as administrator and cleaned project.

I had the same problem but I resolved it using following steps(using eclipse helios and windows XP ) :-
Right click on eclipse.exe.
click on Run As...
Uncheck the checkbox before "protect my computer from unauthorized activity".
And it is running for me as expected !
hope it will also run for you.

Error: Unable to open class file R.java [duplicate]

This question already has answers here:
Developing for Android in Eclipse: R.java not regenerating
(64 answers)
Closed 9 years ago.
Did a fresh install of Eclipse, JDK and android-sdk.
I am currently receiving this error when creating a new project
[2010-09-26 16:07:56 - Test] ERROR: Unable to open class file C:\workspace\Test\gen\com\example\test\R.java: No such file or directory
What's the reason for this and how do I fix it?
Eclipse Helios 32 bit
java version "1.6.0_21"
Android sdk API 8
P.S. I'm new to Android development.
EDIT: I tried most of your solutions, but nothing worked. So I started using my friend's install of Eclipse Ganymede.

I have had same issue, all what I needed to do, was create project and restart eclipse.
//Edit: Complete collapsing of "Package" tree works as well.

This is a mighty annoying error.
It happens 100% of the time when I create a new android project.
What seems to work for me is to just delete the file (which DOES exist and is accessible by my user), then hit build, and it will regenerate it and stop moaning.
It's clearly a bug as there are too many people getting it simply by filling in the boxes in the new project dialog (like me) without even modifying any code!

Have a look at your console. It is an aapt aborted error. Since aapt is the tool that auto-generates R.java, therefore, R.java was not getting generated.
Since R.java is a auto-generated file that stores information about your drawables you should rebuild your project. Before that have a look at your layout xml files and check them for errors.
Notice that Project -> Build All should be selected. Also try to run your project.

Removing Read Only attribute on Eclipse workspace directory and Project->Clean->Build Project
did the trick for me. I then clicked on the project directory from within Eclipse and did a F5 (Refresh) . R.java was generated in the gen folder.

I had a similar error on the creation of new projects myself. After messing around I tried moving the R.Java file into the same location as my projects java file (the src file). Eclipse then saw I removed the R.Java file from its location and created another and that seemed to clean up the error.....I dont know if it was because eclipse rebuilt the file and then saw it or what but that seemed to work for now.

After creating the Project, Right click the Project Folder within the Project Explorer on the Left Tab of Eclipse.
Click on Source->Format.
The Console will say:
[2010-11-24 11:57:42 - YourProject] R.java was modified manually! Reverting to generated version!
Then you're good to go. Try running your Project and it will compile.

Check your imports. If this has sneaked in, then delete it.
import android.R;

Had a almost identical issue with Eclipse Helios 64 bit on Linux, but I had the "1.6.0" API selected like you. The bizarre thing was I could type;
cat <the path it was moaning about>
in a console it would display correctly.
I created a new AVD which used Android 2.1, the issue magically vanished. Perhaps it's a bug in Android SDK or Eclipse?

Right click on your project name in package explorer. Then click 'Validate'. It will be fine.

Here is how to fix it:
Go to your "workspace" folder and make sure it's not "read-only"

Eclipse Menu > Projects > clean

Had the same issue.I was able to solve it by doing the following:
go to Window/Preferences/Java/Build Path
select 'Folders' and change the output folder to 'gen' (this is where Android looks for the generated java files,but the default in eclipse is 'bin').
restart Eclipse
Windows 7,Eclipse 3.5.2

Configure buildpath.. check android , it worked, of course i followed one of the posts mentioned above window, preferences, java, java build path and selected project,
then created a project, and tried to build same error, then i checked build path and saw android is unchecked, checked it and build again, it works!

I had this exact same problem with no helpful errors. finally, I tried deleting my debug keystore and it worked:
rm ~/.android/debug.keystore
I had seen people mention that, but I figured it wasn't my problem because I wasn't getting any errors relating to the debug keystore. I found the answer here:
"Debug certificate expired" error in Eclipse Android plugins
apparently the debug keystore is only valid for one year.

I would say that once you have created your project and you've mention the R.class error --> just restart the Eclipse IDE and everything will be fine ;)

1.-Open Eclipse
2.-Open Window/Preference
3.-Expand JAVA option
4.-Select Build Path
5.-Check the option "Projec"t and uncheck "folder" options
6.-Click on OK
7.-Restart eclipse IDE
Let's go to code !!

This problem can be solved by merely cleaning and rebuilding the project. How ever there is a link to the latest version of Eclipse for Android.
**Eclipse Java EE IDE for Web Developers.
Build id: 20100218-1602
(c) Copyright Eclipse contributors and others 2005, 2009. All rights reserved.
Visit http://www.eclipse.org/webtools**
Here is a link to Android Tutorial with Eclipse
http://developer.android.com/resources/tutorials/hello-world.html

In mac,
I select Project>Clean
after that, i unchecked Build Automatically
then i run the project and it works :)

Windows 7 64bit, run eclipse as administrator, solved the problem for me.

In my case there was no gen folder after pressing clear...
To solve it, i created a new gen file, then when to Build Path => Configure Path, and pressed ok.
All went smooth after that :-)

Following steps are done as solutions:
1. Collapse the project tree structure
2. Go to the workspace and remove the readonly permission of the workspace.
3. right click "default.properties" and go to properties and uncheck the readonly permission in eclipse.( this is done when the workspace shows build error even though there are no compilation issues)

How do I prevent Eclipse from hanging on startup?

I am using Eclipse 3.3 ("Europa"). Periodically, Eclipse takes an inordinately long time (perhaps forever) to start up. The only thing I can see in the Eclipse log is:
!ENTRY org.eclipse.core.resources 2 10035 2008-10-16 09:47:34.801
!MESSAGE The workspace exited with unsaved changes in the previous session; refreshing workspace to recover changes.
Googling reveals someone's suggestion that I remove the folder:
workspace\.metadata\.plugins\org.eclipse.core.resources\.root\.indexes
This does not appear to have helped.
Short of starting with a new workspace (something which I am not keen to do, as it takes me hours to set up all my projects again properly), is there a way to make Eclipse start up properly?

This may not be an exact solution for your issue, but in my case, I tracked the files that Eclipse was polling against with SysInternals Procmon, and found that Eclipse was constantly polling a fairly large snapshot file for one of my projects. Removed that, and everything started up fine (albeit with the workspace in the state it was at the previous launch).
The file removed was:
<workspace>\.metadata\.plugins\org.eclipse.core.resources\.projects\<project>\.markers.snap

try:
cd to <workspace>\.metadata\.plugins\org.eclipse.core.resources
remove the file *.snap (or .markers in Indigo)

In my case (Juno) I had to do this:
find $WORKSPACE_DIR/.metadata/.plugins/org.eclipse.core.resources/.projects \
-name .indexes -exec rm -fr {} \;
That did the trick.
Initially I thought it was a problem with Mylyn (I experienced these freezes after I started using its generic web connector), but the problem appeared even after uninstalling the connector, and even deleting the .mylyn directories.
Edit: I also managed to restart eclipse by deleting just one file:
rm $WORKSPACE_DIR/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi
That worked fine, without any indexes involved. Only the workbech, which I personally don't mind that much.

You can try to start Eclipse first with the -clean option.
On Windows you can add the -clean option to your shortcut for eclipse. On Linux you can simply add it when starting Eclipse from the command line.

This one works for me:
Another, and a bit better workaround which apparently works:
Close Eclipse.
Temporary move offending project somewhere out of the workspace.
Start Eclipse, wait for workspace to load (it should).
Close Eclipse again.
Move the project back to workspace.
Source: Eclipse hangs while opening workspace after upgrading to GWT 2.0/Google app engine 1.2.8

I used eclipse -clean -clearPersistedState and that worked for me.
Warning: This may remove all projects from the workspace.

I had a similar problem with a rather large workspace in 3.5 and no .snap-files anywhere to be seen. "Windows -> Preferences -> General -> Startup and Shutdown -> Refresh workspace on startup" seems to be a workspace-related setting and so I couldn't change it for the workspace that was causing the hang.
Running eclipse with the command line parameter -refresh and then changing the setting seems to do the trick.

I also had luck with removing the *.snap files. Mine were located in a different directory than mentioned in the posts (below).
<eclipse workspace>/.metadata/.plugins/org.eclipse.core.resources/.projects
Consequently, the following unix cmd did the trick:
find <eclipse_workspace>/.metadata/.plugins/org.eclipse.core.resources/.projects -name "*.snap" -exec rm -f {} \;

I tried all of the answers in this thread, and none of them worked for me -- not the snap files, not moving the projects, none of them.
What did work, oddly, was moving all projects and the .metadata folder somewhere else, starting Eclipse, closing it, and then moving them all back.

Since I don't have a .snao or .prefs file in .metadata.plugins\org.eclipse.core.resources folder (running on OS X), what did the trick for me was copy the .project folder to old.project, start Eclipse, and check
Windows -> Preferences -> General ->
Startup and Shutdown -> Refresh
workspace on startup
as proposed by matt b. After that, I closed Eclipse, renamed the folder old.projects back to .projects and after that everything worked fine again.

I did this:
cd to .metadata.plugins\org.eclipse.core.resources
remove the file .snap
Noticed the Progress tab was doing something every few seconds..it seemed stuck
Exit eclipse (DO NOT FILE|RESTART HERE OR YOU HAVE TO GO BACK TO STEP 1 AGAIN)
Open eclipse again.
Using -refresh or -clean when starting eclipse did not help.

On Mac OS X, you start Eclipse by double clicking the Eclipse application. If you need to pass arguments to Eclipse, you'll have to edit the eclipse.ini file inside the Eclipse application bundle: select the Eclipse application bundle icon while holding down the Control Key. This will present you with a popup menu. Select "Show Package Contents" in the popup menu. Locate eclipse.ini file in the Contents/MacOS sub-folder and open it with your favorite text editor to edit the command line options.
add: "-clean" and "-refresh" to the beginning of the file, for example:
-clean
-refresh
-startup
../../../plugins/org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar
--launcher.library

Check that the Workspace Launcher hasn't opened on your TV or some other second monitor. It happened to me. The symptoms look the same as the problem described.

Windows -> Preferences -> General -> Startup and Shutdown
Is Refresh workspace on startup checked?

I just had problems with Eclipse starting up. It was fixed by deleting this file:
rm org.eclipse.core.resources.prefs
I found in .settings

UFT causing issues with RDz (Eclipse based) after install
These suggestions will allow to work around this situation even with the environment variables in place and with corresponding values.
Note: Conflicting application will not be recognized in a java context because it is being excluded from the java support mechanism.
Impact: Excludes Add-ins support from hooking to conflicting application executable via Windows Registry Editor
Requirement: The application must be started by an EXE file, except Java.exe/Javaw.exe/jpnlauncher.exe
Instructions:
a. Locate the executable filename of the application conflicting with add-in(s) support. Either use the Task Manager or the Microsoft Process Explorer.
b. Open Windows Registry Editor.
c. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Mercury Interactive\JavaAgent\Modules
For 32bits applications on Windows x64: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mercury Interactive\JavaAgent\Modules
d. Create a DWORD value with the name of the conflicting software executable filenmae and set the value to 0.

Removing *.snap (mine is *.markers), --clean-data or move workspace folder seems all did not work for me.
As my eclipse stopped working after I installed and switched my keyborad input to HIME, I went back to fctix and it worked.

I had no snap files. Going through the help menu installation list, at least 90% of my plugins had the uninstall button deactivated so I could not handle it through there. Under startup/shutdown most of plugins were not listed. Instead, I had to manually remove items from my plugins folder. Wow, the startup time is much faster for me now. So if everything else does not work and you have plugins that are disposable, this could be the ultimate solution to use.

Unfortunately, none of these solutions worked for me. I ended up having to create a new workspace, then imported the existing projects into the new workspace. Unfortunately, you lose your preferences when doing so (so, remember to export your settings anytime you change them!)

I had a very similar problem with eclipse (Juno) on Fedora 18. In the middle of debugging an Android session, eclipse ended the debug session. I attempted to restart eclipse but it kept haning at the splash screen. I tried the various suggestions above with no success. Finally, I checked the adb service (android debug bridge):
# adb devices
List of devices attached
XXXXXX offline
I know the android device was still connected but it reported it offline. I disconnected the device and shut down the adb service:
# adb kill-server
Then I waited a few seconds and re-started the adb service:
# adb start-server
And plugged my android back in. After that, eclipse started up just fine.

no need to delete entire metadata file. just try deleting the .snap file from org.eclipse.core.resources on your workspace folder
ex. E:\workspaceFolder\.metadata\.plugins\org.eclipse.core.resources

Watch out for zero-byte .plugin files in the {WORKSPACE-DIR}/.metadata/.plugins folder. I just deleted one in there and it fixed my freezing issues.

In my case similar symptoms were caused by some rogue git repository with a ton of junk system files.
Universal remedy, as mentioned above, is to use Process Monitor to discover offending files. It's useful to set the following 2-line filter:
Process Name is eclipse.exe
Process Name is javaw.exe

I had a similar problem after I updated eclipse on Mavericks. Eventually I found that in the eclipse plugins directory the com.google.gdt.eclipse.login jar had version numbers at the end. I removed the version number from the name and it all started fine :)

Also look at http://www.lazylab.org/197/eclipse/eclipse-hanging-on-startup-repair-corrupt-workspace/
99% Recommended Solution works.... (i.e. Removing .snap file) But if it did not worked then we have to try to remove indexes folder and further workbench folder.

This may help
In your eclipse,
1) Go to Help
2) Click Eclipse marketplace
3) search - optimizer
install "optimizer for eclipse"

In Ubuntu eclipse -clean -refresh worked for me for Eclipse 3.8.1

It can also be caused by this bug, if you're having Eclipse 4.5/4.6, an Eclipse Xtext plugin version older than v2.9.0, and a particular workspace configuration.
The workaround would be to create a new workspace and import the existing projects.

Well, I had similar behaviour while starting eclipse over X11. I forgot to tick the enable X11 forwarding in my putty.

In my case deleting the .metadata folder of the workspace worked. I am using Eclipse Luna service Release 2.