When opening parts or drawings, my CommandManager works just fine, but when I open an assembly, it looks like this:

That is, all the other tabs are gone, and nearly all the commands are gone from what remains. I've never seen this before, and suspect registry corruption or similar. It worked fine just yesterday. I searched forum for similar, and others had entire ribbon hidden, not emptied like this. Ref. Spec: SW Premium 2016 SP3.0 on Win7 Pro.

I plan to restore UI with Settings Wizard, which I hope will work, but wanted to know:

What may have caused this (maybe it's avoidable)?

Will this likely happen again?

Could this be due to something outside of SW, such as Windows Update maybe?

Is Settings Wizard the best solution, or would I need to shoot my productivity in the foot today with a reinstall?

Thanks folks.