Can't create a termbase because guess what? not a valid name.

What a weird reason not to be able to create a termbase. I just bought SDL Trados Studios 2021. MultiTerm is a nightmare to use(I know how to use it, I used older SDL MultiTerms before. why does the 2021 version still have the same problems?). I can't create a termbase because of the name and it's ridiculous. I tried all solutions. I'm so close to giving up. why does this problem even exist? what's the point??

SDL MultiTerm 2021

SDL Trados Studios 2021

I would really appreciate all the help I can get.