Clonez,
Your other question was the same question; this is to keep all possible answers consolidated so we can track what works and what doesn’t work. Please only open a new thread for a different issue.
Have you attempted the fix suggested by MrFred, that the material he linked has become corrupted? Did you run the verify content? Have you tried removing that material from your project?
Further, we have submitted a issue for this, and it is listed in the other comments. We will absolutely update here when we have more information regarding this problem.
Thanks very much.