I have the very same problem with you, and I don't know what caused it, but at least I've found a way to "fix" it.
It seems there's a glitch on the material/nodegraph editor that causes the problems.
You can look at the "first material/material 1" node/section. And then see the "texture 2 / RGB image" section.
It's empty. So you just enter the specific texture there (usually the face texture). And then set the power to RGB and choose the white colour like usual.
I hope it can help you.
(or better you have found a better solution/fix)