This has been going on for “a while” and not all the time [one of those, yes] - I launch Rhino and the splash screen comes up but gets stuck at some stage loading plug-ins. Most of the time, I click (X) the splash screen away pretty much immediately and after a few minutes with nothing happening, I launch a new instance of Rhino. Most of the time, that one will get through loading all plug-ins and the UI appears. Trying now, that second instance also got stuck and a third one opened up.
Those times that I have tried to see what’s being loaded, the first instance of Rhino has always stopped up at loading Bongo for Rhino 6. The second launch will get stuck on some other plug-in.
I end up with a crash (in its zoological meaning) of Rhino processes but only one with visible UI:
Launching in safe mode is instant.
Load-protected Bongo and launching regular RH6, it loads the other plug-ins and launches without problems.
[While at it, after having installed Bongo for RH6 (with no Bongo for RH5 present), launching RH5 will show this each time] :