android - After add images to drawable "Cannot resolve symbol R" issue not going away after clean, rebuild etc

Question

I can't find a way to add images to drawable folder without getting "Cannot resolve symbol R" issue.

And once i get "Cannot resolve symbol R", I can't get rid of it by either clean, rebuild, sync, invalidate cache & restart solutions for the error. Only if i delete the files can I get the build to pass.

I am not sure what is wrong here.

Note: I am on Android Studio 2.1.1

Answer 1

I had exactly the same problem, and it was that I downloaded an "image.jpeg" extension from Internet and directly changed the extension saving it like "image.png", but Android studio still recognized it like image.jpeg.

I realized that when using top menu Analyze-Inpect code.

Once the inspection is finished a new window called 'Inspection' appears and in the follow carpets appears next:

Android > Lint > Usability > Icons
Icon format does not match the file extension

     Misleading file extension; named .png but the file format is JPEG*