Something went wrong: there was an error publishing your course - How to resolve

My colleague just had this same problem. She found out that some of the new features (images as backgrounds and so on) were causing this on her new courses. She removed those, and it worked again.

All those were working yesterday just fine, so this might something that will get fixed soon back to normal.

I'm not sure if this limited to those newer features, or if there are more elements that are currently broken.