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R.java was modified manually! Reverting to generated version

I added one xml file in layout. After that this error is coming. But the problem is I haven't touched R.java file.
Now in my new activity i m going to set its content view as my newly created xml file, but when i m doing R.layout., the newly created xml is not coming in suggestion. Do anybody have any idea how to correct this.
I have cleaned my project several times but it is not working.

Delete R.java and let eclipse regenerate it, then project --> clean will fix it.

Check if you have any existing errors in your code, if yes correct it and then try refreshing and building your Project.If your Project is properly build,you will get the new xml file in suggestion

It happened to one of my Eclipse projects today. This is what fixed it mysteriously. Don't know why or how.
Changed Properties->Android->Project Build Target to a higher (different) version of Android and hit the Apply button. Then did a clean build. The problem went away.
After the above steps, I could even go back to the original Project Build Target without the problem re-appearing.

May this Help you...
I think your xml file name might be having some capital letters or some special characters..
Delete them and then try again to run the project..

Try cleaning the project this will do the work.

make sure your not importing any thing that ends with com.R
make sure your naming convention of the layout is correct

R.java file have all the resources IDs provided to resources(drawables, layouts, styles etc) either by Programmer, or generated through sdk. So check your xml files as well as your drawable folders. If any of them including wrong format it will show an error in R.java file like sometime R.java is not generating or our class file shows R.id.xxx is not found or R.class is not defined error.Then clean your project.

There must be some mistake in one of your xml files. Eclipse does not always show error messages if there is something wrong with your xml. Mostly code gets errors, in this case 'R', so you will need to go through your xml manually, it could just be a simple mistake. Good luck

I had similar problem. Cleaning project didn't solve the issue and there was no error in the code or the uppercase or spaces in file names.
The solution was going to a popup window which came when you choose PROJECT-->CLEAN and then UNcheck the "Start a build immediately" option. Clean the project. Close and reopen Eclipse and then build the project (PROJECT-->BUILD).
The question remains why simple clean and build without closing Eclipse didn't worked.

Right Click on Project->Bulid Path->Configure Build Path
ther you see error android-support-v4.jar remove this library and add library again this works fine for me.
Else
Try
Go to gen Folder delete R.java and from Project option choose Clean Project.

Very late on the scene...
I had this line mysteriously appear at the start of my imports:
import android.R;
I deleted it and shazam error was gone.

I had similar error, but when I import new project to my eclipse. and the solution was, I should check the option (copy project to work space) specially when our project has library.

Resource file can't be located by eclipse android

I need help badly. I tried to to a clean in my android app Project>Clean. After doing this, All my classes started to have errors. It can't detect the R in --> findViewById(R.id.heightVal); And it cannot locate some other files, xml ids and xmls. Any ideas?

I think you import android.R in your activity . If it is the case then delete that line and clean project again.
R is an automatically generated class that holds the constants used to
identify your resources. If you don't have an R.java file (it would be
gen/eu.mauriziopz.gps/R.java in Eclipse with the 1.5 SDK) I would
recommend closing and reopening your project or going to Project >
Build all (and selecting "Build Automatically"). If that doesn't work than try making a new
project.

this might help you if you are using Ganymede and in some other versions of eclipse had experienced similar problems either restarting or doing this cleared it most of the times
right click on your project then click configure build path tick the android file shown there

Try to comment all the lines in XML file that show an error.
Clean up the project.You can uncomment the lines if R.java has been regenerated.
If the id's are still not detecting try closing and reopening the project.Its weird but sometimes you have to do it.

Error showing on every project in Eclipse and I haven't changed anything

I have just opened Eclipse as I need to make some changes in an existing project. I added a new file to my 'Raw' folder and refreshed the folder and when I went to build it shows a error 'x' on the project but not against any of the source files, etc. It also shows an error against every other project in Eclipse even though I haven't touched any of them
If anyone has come accross this problem before please let me know how I can rectify it.

I have several times problems with Eclipse highlighting everything with errors even when everything is fine.
Sometimes it looks like Eclipse caches the errors and does not clear them properly.
In those cases, I tried different things such as:
removed the file you just added. Refresh and clean the project and see if it has fixed it.
Remove project from Eclipse and import it again.
Close Eclipse and open it again.
For me, the above sometimes work.

The issue might with unresolved build resources. like some previously used path might not be available now. You can goto the properties of the project and check in the respective tabs if some of the paths earlier set are not valid anymore.

I've managed to resolve the problem. You need to delete the debug.keynote file in .android which had expired! Then clean and rebuild your app and the debug.keynote file will be recreated and the error removed.

R.java disappears after project clean

After I added some .png files into my Project Workspace drawable folder I refreshed my drawable folders in Eclipse and the newly added files showed up. But when I tried to access those resources using R.drawable.xyzimage, xyzimage although in the folder could not be resolved.
So I did a Project Clean and guess what after this clean R.java is totally gone and all my classes accessing resources using R.java is showing all sorts of error and Eclipse won't let me run the code anymore.
I have backup of my source code but I want to explore if R.java can be regenerated and how?
Thanks for all the help.

Try Project->Clean in Eclipse. In my limited experience if R.java is not being automatically created then there is an error somewhere in your xml. Triple check everything.

You have to build the project to be able to use the newly added resources.
Cleaning a project removes all auto-generated files. Building the project it should automatically create them. When you Clean a project, there's an option to start a build immediately after clean up.
Here's a few things you can try (did the same procedure after manually deleting the "gen" directory.
After you have deleted the gen directory, go to Project > Clean ...
You should have errors indicating that R cannot be resolved to a variable. Right click on your project from the Package Explorer and select Build Project. Be sure Build Automatically option is turned off (uncheck in Project > Build Automatically).
Errors regarding R should have now disappeared. Now, perform a Project Clean once again. All errors should be gone.
Let me know if this works for you.

Here is what the problem was. I added those new png images to the project and android has rules as to what characters are allowed in the names of these images. Once I changed the uppercase letters in the image name, it was back on track again and Build Automatically generated the R.java file and all errors were gone. Eclipse console is the place where I found all the errors related to my resources.
Thanks Guys....I tried your solutions but my error was something specific which was due to my image naming convention so this is the way I fixed it.

I would agree this is usually a XML problem but moreover that it is something within your res folder that is the problem and may be highlighted with a red cross after the clean attempt.
I have just had this problem and it was because I had created my own folder called 'data' within res folder. After the clean it had a little red cross against it. I removed this folder and R built again.
Regards,
Mark

Several things you should check in your project:
Check the Problems tab in your Eclipse IDE. Are you sure that you did not introduced building problems while making changes with drawables? To check that you need to check xml source of affected layout and see if something is marked red.
In File explorer go to the directory where your Android project is. Check that you have file default.properties (.classpath, .project and AndroidManifest.xml should be there). If default.properties is missing it may be easily replaced by correct version.
Which is the Android version you are working with? If that is 1.5 or lower be sure that in the res directory you have directory named drawable, not drawable-hdpi, drawable-mdpi and drawable-ldpi. Last three are valid for version 1.6 and higher.
Right click on your project in Package explorer in Eclipse. You will get a number of options. Go to Android Tools-> Fix Project Properties so see if that helps.

I had an invalid jpg in my res/drawable folder. I removed the jpg and it worked.

I had this problem on my Mac too and I think it could be good to know for all Mac users how I managed to solve this error.
I had a .DSStore file automatically imported to my project inside the res directory and when I removed it and rebuilt the project all went well.

Everytime you clean the project and it rebuilds, it imports
import.android.R
so, delete this import and remove all errors from xml files. It will work.

This happens to me if I move my project to a new location. I have found that the answers above didn't fix my problem, but that creating a new project and importing the source did.

This may be simple but check to make sure you don't use
import android.R;

If you add an external resource file with capital letters for example
"Hello.png or WelcomeSound.mp3 etc etc" like if you add upper case letters and clean your project you'd surely loose your R.java file. So if you already lost it, either rename the file externally and then clean your project or else right click on the project Refractor->Rename and then rename your file with all letters in lower casing. Next, delete the 'gen' folder in the project explorer and now right click and "Build Project". If Build Project option is grayed out, go to Project-> Deselect "Build Automatically" option.
Regards,
Kshitij Thube

Check at the Console View If there in message Error, It will Help you to find out the source of the probleme.
I had i similar probleme and i find out that the probleme was from the pic name even if the name respect the Syntax so I change it to img1 and it worked fine.

Try editing one line of code in your project, then build the project once more.

Another thing: never try to run an application with the texteditor opened with a xml file. That will create a wierd run configuration that can only be fixed by project clean-up and sometimes can make the xml file to vanish (happened to me twice already).

All my R.* files stopped working after I did a Project->clean in Eclipse. The issue was that I backed up a XML file attached to one of my activities in the layout directory. This causes errors in every activity of my project.
After deleting the file I still had R errors in one of my Activities and it only was resolved after I tried importing different files and then deleting them. I actually made no change to the previous imports but for some reason deleting them all and re-pasting them fixed it.

I have got the same problem after lots of cleaning and building project again and again. I found that on console there is this error:
res/drawable-hdpi/Blue Blank.png: Invalid file name: must contain only [a-z0-9_.]
and this is not appearing as an error in xml. I changed the name and save the file, clean project and build. Now it's working. My suggestion check your res folder and name of files you use in it and name only [a-z0-9_.].
Delete related tag in xml, save xml, clean project, build project. Now again put that resource in xml and save!

Check your file in drawable folder ensure that all are resource file (image) remove unwanted file Like thumb.db. Remove those all files and check again

Make sure your png files have lowercase names. That is what kept throwing mine out, because I capitalized the first letter, or I used an unallowed non alpha numeric in the naming. Check that before destroying any of your code.

just check your image folder (usually created res > drawable files) and be sure dont use capital letters on .png files, every type must be in small letters then you can find again your R.java under the gen file folder

i removed 'import android.R;' then commented out the offending lines, then did a build, ok
then i removed the comment and it fixed it

I had the same problem when I cleaned my project. I got crazy to solve it, I searched and searched but solved it in my way.
First of all, delete all needless files in your /res folder. I had some notes in it, I took them to another project that I don't work on it and build the project manually. It worked! Try this I'm sure it will help.
Good developing!

Was there an XML file with the naming convention of "somthing.out.xml" generated? If so you should delete this file (an unwanted file of this name can cause major problems for your somthing.somthing.R file import).
In some versions of eclipse (I know eclipse javaEE does this for sure), running the project while viewing an XML file will create a file called filename.out.xml in your res->layout folder. You must delete this generated file if this has occurred otherwise you wont be able to get the java.R file to import.

Try Project -> check Build Automatically

If you are using 64-bit Ubuntu, try to install the 32-bit libraries (ia32-libs)
$ sudo apt-get install ia32-libs
it worked for me

This exact same thing happened to me. coincidentally I needed to update my adk that day, so i did so and after restarting eclipse it worked again. My recommendation would be to build the project and restart eclipse. It is not due to any error in your code.

I read and tried many of the above after simply doing a clean on one project. Eclipse would not build anything afterwards.
Fortunately I had last-nights backup of the workspace and my source is copied in from VS 2010.
No more cleaning!

Delete your project from workspace witout source deleting and then import it into workspace.
RightClick on your Project -> Delete /Don't select "Delete project content on disk (cannot be undone)"/ -> Ok
File -> Import -> General -> Existing Projects into Workspace -> Brouse -> /Look for your workspace(!) folder/ -> Ok -> /your cleaned project will be automatically checked/ -> Finish

I had the dreaded missing R problem yesterday with Eclipse Juno after a routine clean. StackExchange is full of suggestions and extensive googling revealed only the usual suspects (XML naming conventions problems, etc) none of which seemed to apply directly, although it is certainly possible I missed something.
The best summary comprehensive list of possible causes and fixes was here:
http://www.techrepublic.com/blog/software-engineer/a-comprehensive-troubleshooting-guide-for-androids-r-cannot-be-resolved-error/
One useful tip there was to try to create and run a simple "Hello World" in my workspace. If that does not run, the setup is corrupted. My Hello World was just as full of errors as my custom app.
The solution that worked for me (perhaps great overkill but nothing else worked) was to completely uninstall Android SDK and delete Eclipse (Juno), download Eclipse for Developers (Kepler) and reinstall Android ADT plugin and ADK and recreated my AVDs using the latest "compile with" version in options.
So far so good, although I am recreating the app from scratch. I will be more cautious about using clean from here on.

I have same problem occur just now I renamed invalid png file like *demo.1.png as demo.png * and its work.

Proven successful method, check the file (AndroidManifest.xml) and delete all comments in it, and make sure there are no errors in this file, I tried and did work with me.

Magic behind R.java file

Recently I have been having quite some problems with R.java file. Now I have decided to do a backup and delete the file to see what happens.
Nothing happened, so I created an empty R.java file and hoped for the best. Now Eclipse seems to figure out that the file was tampered with and even issues a warning:
R.java was modified manually! Reverting to generated version!
And that's all there is. I tried building it manually but got no results.
So, I have two questions:
what should I do to force Eclipse to regenerate the file
what is happening here? How is the file created, where is the code that is generating the file?
I would appreciate any help. As usual the problem occurred just a few days before the deadline :)

I had a problem getting my Android app to compile, with seemingly inexplicable errors about failure to generate R.java.
The problem was caused by my previously killing the Android emulator during the build. Don't do that! A clue was the appearance of several left over *.out.xml files.
The solution was to select the project, click Project->Clean, and then manually delete all the *.out.xml files. Only then could I click Run->Run and have a successful build.
One more thing: I'm using Eclipse. I had to make sure that the project was selected in Package Explorer, and not just some random source file. Easy to not notice!

R.java is autogenerated on build. It's content is based on the resource files (including layouts and preferences).
When you deleted it, it was recreated, but if you create your own, you will get into trouble as the build system will not replace it.
You can simply delete it again (manually or by choosing Project->Clean) and rebuild your program.

I had this problem several times, and most of the times it is caused by some mistake in the "res" files, check everything is OK in all your res files, mainly XML, and after you can built.
For example, two common causes of this problem can be:
Didn't properly spell the name of a property in a Style in a XML file.
Didn't properly close a string in the XML of a locale file.

I found the problem - I have created a 9patch image with the patch area defined only on the Y axis (I was trying to prevent resizing on the other one).
The question remains: Why isn't there a warning about the error? Or if there is - where is it buried?

Sorry, but try to check the output in Eclipse. May be you have some errors that prevents Eclipse to finish build proccess(check your AndroidManifest.xml, is it correct?).I mean, that you should check all your resource files(string.xml, layouts, ...) and interfaces(*.aidl), may be there are some problems(inconsistent syntax, or something....) that prevent eclipse to generate R.java.

I had the same issue and it was that I had named a resource file (a .png image) using uppercase letters. (ImageButton001.png instead of imagebutton001.png).
Afther changing the name of the file my R.java came back.
Rgards,
Juan

If there's insufficient free memory the build tool will silently fail (Eclipse will not show any errors or report anything in the error log). Close your other open applications (e.g. the emulator and browser) then add a space to the application manifest file and save it.

As ponkin stated - you probably have one single problem that causes R not to re-generate itself, because of which you now have one million and one problem.
Do not try to create R class yourself. Try to think of the last XML you've been messing with, and check it for errors
I've had the same problem here

Make sure there are no errors is your Manifest file.
If you delete the resource string app_name in /res/values/strings.xml, it doesn't know how to generate R.java right.
I found this a problem when doing the HelloSpinner tutorial.

I found that an unwanted resource was causing an issue. As soon as I deleted the resource R.java was generated.

I've had this problem, to rebuild R.java I cut the code in the xml file I've just been working on (or try others if this doesn't work), deleting the file then creating another with the same name and pasting the code back into it. Hope this helps.

Something that can be good to know is that if an XML file contains a ?, then R.java is not regenerated and the error is not shown in the XML file (sometimes it shows up after a while)
I you have a line similar to:
< string name="questionmark"\>?< /string> <br>
try to change the ? to something else and see what happens to the R.java file - worked for me

I had a similar problem, I had renamed a .wav file in the Raw folder with a capital letter. When I changed to all lower case, cleaned the project and it rebuilt R.java fine.

As others stated, stay away from creating your own R.java file. I ran into the same problem when I first started with Android, and it took some time to figure out what caused by compilation errors.
What were you trying to do with the R.java file?

I had the same problem. I just went to:
Project -> Properties -> Android
and chose the right Emulator for my project, I had 3 different to choose from in that moment. I realized that i changed the Emulator in some given moment. So try to change the Emulator, that might help!
Good luck

I had the same issue with IntelliJ. The problem was that I had app_name defined twice in strings.xml For some reason, IDEA inspections didn't pick this up automatically.

I read this on another site and it helped me:
"If that doesn't fix your problem, try modifying your AndroidManifest.xml (just add a space and save). I've heard that will force the R.java to rebuild. "
So just add a space in the manifest file and then rebuild!

As a side note, usually those *.out.xml files are generated by trying to build your project whilst an xml file is focused in the editor

I had similar problem.Cleaning project didn't solve the issue and there was no error in the code or the uppercase or spaces in file names.
The solution was going to a popup window which came when you choose PROJECT-->CLEAN and then UNcheck the "Start a build immediately" option. Clean the project. Close and reopen Eclipse and then build the project (PROJECT-->BUILD).
The question remains why simple clean and build without closing Eclipse didn't worked.