解决方法：In my case, the error was caused by a png file I added to the drawable folder. I had changed its extension from jpg to png by changing the text (inproper way) and then uploading it as png.
This was the problem Android Studio was pointing to.
I fixed this problem and got the error to disappear by changing the file extension using paint.net tool (proper way), and then uploading it to the drawable folder.

答案：http://stackoverflow.com/questions/30764604/execution-failed-for-task-appmergedebugresources-crunching-cruncher-png-fa