Error:must Have One-pixel Frame That Is Either Transparent Or White In Android Studio

I have just imported a project from eclipse to Android studio. Almost for every second image , android studio is giving the following error. Error:Must have one-pixel frame that i

Solution 1:

This is shown because you're trying to edit 9-Patch images that don't have the appropriate 1-pixel border.

Android uses an image format called 9-Patch which allows you to define stretchable areas in an image (you can read more about it here). To fix your problem, either add an outer 1-pixel thick transparent frame to your png images or simply rename them from .9.png files to .png files