TexTools for Blender

I Installed the TexTools Addon on my Blender 2.8RC1 (RC2, and 2.8 as well), get the error when I try to Bake maps. I see in replies that it is working on RC1 for some others.

What can cause that?

ps.
Im big fan of this tool since it was realesed as plugin for max years ago…