Studio One 5.5.1 appears to be borked on my PC (but not my Mac). After a project scan is done it just hangs (with horizontal barber pole twirling).
The only project I can open is when I create a brand new project.
I'm going to revert to 5.5.0 and see if it solves the problem (that was my last install).
[EDIT] It was not 5.5.1. There is some problem with Spectral Layers (VST3) so for now I deleted it. Maybe the Cubse 12 install borked Spectral Layers.