ff works not working anymore

Hi updated to Golden Gate dev beta 5.
I'm having an issue that already started on the previous beta for some reason : the ff works app 5.2, although stated being MacOS 27 ready, doesn't launch anymore. Getting

An exception of class NilObjectException was not handled. The application must shut down.

Contacted support, stating they're not aware of any issue (thanks dudes !).
Tried complete uninstall and reinstall, to no avail.
Anyone ran into the same issue and/or has a fix ?