Android Studio: Refactoring cannot be performed when importing images

Question

All of a sudden this morning I am unable to drag png files into my drawable folders in Android Studio. I get the message "Refactoring cannot be performed - the file is read-only". I have confirmed that these files are not read only and have tried this with numerous image files in different locations on my Mac. Any ideas as to how this can be fixed please?

PS - This is occurring in all my Android Studio projects. I am running Android Studio 0.5.9 on OS X 10.9.3

Answer 1

I managed to solve it somehow. Just copy and paste the *.png you need in your drawable folder instead of dragging it. Turns out there's a problem with moving it

Later edit: holding ALT whilst dragging the files should also do the job. Thanks @RunLoop