I had this problem for a while and was able to solve it myself.
If in opening your project in Android Studio and something similar to this error message pops up:
I have encountered similar problem many times, and there just one thing that can be done to solve this.
step 1 : delete the .xml files containing error, or cut and paste to some backup folder if you want to inspect that file later on. However, it's unlikely that you'd find anything.
step 2 : try to open android studio after having deleted those files, it must be running perfect. if it doesn't and still contains errors try 'invalidate catches and restart' option in file menu.