AAPT error: resource drawable/... not found
In my case it was an xml selector. In the first line I had two of these (thanks to copy paste among my files):
<?xml version="1.0" encoding="utf-8"?>and Android Studio didn't give any warning or something. Removing it fixed the problem but it needed a full clean build afterwards.
I fixed the error, which was probably coming from a mal-formatted copied XML file (probably some line-ending confusion)
Rewriting those fixed the error, although Android Studio displayed another file as the source of the problem, which in fact had nothing to do with the error itself.