That was the point: it could not be created because at some point (either on install or on first launch) a file without file extension was created that was named the same way as the customization folder (for example "Autodesk Revit 2022"). Because a file with that name was already there, Revit could not create the customization folder (each name can only exists once in a given directory). That doesn't actually prevent revit from launching but it does prevent settings from being saved, and apparently it also caused the Enscape ribbon to be completely greyed out. Deleting the file and restarting revit worked.
That's not to say this is the only possible cause of a greyed out Enscape ribbon of course.
Thanks Pieter, can you be more specific about the files and paths? To my knowledge, both Enscape and RIR plugins (ADDIN files) are located in %Programdata% folder:
C:\ProgramData\Autodesk\Revit\Addins\
and not in the Roaming profile
When you say "file without file extension" are you referring to something below? We call these "stub" files which look like folders but they are actually files. These can compromise installation of the software, i.e. during the installation it expects path to be accessible for application to place ADDIN file in but if it doe snot get what it wants it will simply fail. deleting these Stub files resolves the issue.
C:\ProgramData\Autodesk\Revit\Addins\2022 to be accessible but if "2022" is a file