Whenever I try to add a 9-patch image to the \\drawable folder in my project, I get the same error:
\\drawable
ERROR: 9-patch image C:\\...\\res\\drawable\
Your 9-patch can be wrong.
Maybe you strip 9-patches one-pixel borders away and information gained from them is not available. Try to add a bottom line and a right line for text too. I think it will help to solve your problem.