Well, like I said, I was switching between MAC and PC. It worked fine on the macbook, but once I opened with my PC, the brushes becomed black.
So far the only solution I found is find another mac and do the export, because on mac I don’t have this issue.
I guess it’s a After Effects’s version problem. On mac AE is CC 17 latest update, and CC 17 not up to date on PC.