basicwiz opened this issue on Apr 23, 2012 · 560 posts
hborre posted Sat, 03 August 2013 at 9:07 AM
Your description doesn't give much information to go on. Basic has mentioned one solution, but I suggest posting screencaps of Render settings, Mat Room, etc to give us a better understanding. There are several issues that do come to mind, but randomly elaborating on each solution may not answer your particular problem.