Develop Reference

I am getting error in android studio "Unable to load class 'com.google.common.base.Optional'"

I am getting this unexpected error and I tried re-installing the Gradle file still I am facing the same error I even tried rebuilding the project but when I create a new project it gives the same error called "Unable to load class 'com.google.common.base.Optional'.",
"This is an unexpected error. Please file a bug containing the idea.log file."

Try deleting your .gradle directories from both in home directory and at the top level of tthe project.
Questions with similar issues
Android Studio: Unable to load class 'com.google.common.base.Preconditions', Gradle Sync Failed

I'm getting error in "this.something" in all activity and mainfest, xml of android studio

I just installed android studio because I reinstalled windows.
While opening my project, at first I got error in every where. Then I
clean and rebuid the projects
sync the project with gradle file
invalidated caches/restart
deleted .idea and .gradle files
auto import
[UPDATE: I again invalidated caches/restart and it worked :)] But, how can I solve this warning?
I got this warinig while rebuilding the app, might this be reason of showing error?
error while rebuiding
My errors as compared to before are gone but I'm still getting the errors in xml, manifest, actvities.
error in xml
error in mainfest
error in activity
error in activity
error is DataAdapter
I think there might be issue of importing internal files from one to another but don't know to sove this. and, I don't know why I'm hiding package name, but I think that is good practice...?

Add ndkVersion to your module's build.gradle
android.ndkVersion "your-installed-ndk-version"

Getting the could not find method error in android studio while trying to run the app

After setting up all the things in the design and code, I tried to run the app but this error pops up, there's no error in the code. I will be glad if someone can help me. Thank you.
Error:
Could not find method andorid() for arguments[build_9gmycv9fddo910sgl0ixcpq11$_run_closure1#1e9e8070] on project ':app' of type org. Gradle. Api. Project]

Normally that happens because you are using the wrong build.gradle file and mixing the top-level gradel file with the app module gradle file
can you post both of these build.gradle files

It might be the gradle issue.
Click on File -> Invalidate Caches / Restart

Failed to create parent directory when I start a new project?

I tried each and everything possible like updating my Android Studio, enable gradle in offline mode, in fact I reinstalled Android Studio two times at different location but nothing is working, every time getting the same error:
Error:Failed to create parent directory 'C:\Users\professional.gradle\caches\modules-2\files-2.1\com.google\google\1' when creating directory 'C:\Users\professional.gradle\caches\modules-2\files- 2.1\com.google\google\1\c35a5268151b7a1bbb77f7ee94a950f00e32db61'

The error is solved after deleting the complete activity file and XML file in it, creating a new activity and then just cleaning and rebuilding your project will resolve the error and run the app.

error R.java No such file or directory found

My project shows error in r.java.It was working fine before,all of sudden it says R.java is not found.When I tried to delete gen,gen file is generated automatically in which R.java showed error,
I tried cleaning my project,build path,deleted debug.keystore.But,of no use.
Could anyone help in resolving this issue.I am able to build new project,its all fine.The problem is only with one project

I have somehow managed to fix it, but I don't know exactly what did it. Here are things I did.
Deleted eclipse directory and reinstalled it and ADT.
Deleted my original project that was the first to have the problem.'
Created a new project with my original's project name.
Manually copied all my class and res files into the new project and
refreshed it.
Pasted the text of the old manifest into the new manifest.
I did all this, because simply importing the original project again didn't solve anything.
After the above changes Your Project will be Fine.

I have faced same problem. simply i delete my r.java file and restart eclipse then this problem is solved.