I had exactly the same problem.
12.5.6.0 is totally buggy, no UI, crash, no menu. I'm French too, is it the language file the problem ?
I try dirty flash first, crash!
Clean Flash, crash !
Change for TWRP, OrangeFox, PitchBlack, same crash !
I did a clean install of 12.5.5.0, no problem.
I saw...