Maybe it’s because of an update of your operating system. I’ve had one last night…
After the deinstalltion just delete all the folders and what’s inside. I would also deinstall the VST3 version and everything else about the plugin. When you’re reinstalling again, VST2 and VST3 will usually be installed at the same time, unless you decide not to. In terms of Renoise this “should” help, regardless of what’s happening in other DAWS just like Ableton Live.
Hm, I never had any problems with any VST3 that I’ve used. No GUI issues, no dysfunction, nothing. I don’t know, maybe I’m lucky or maybe I don’t use the “wrong” plugins. Are you talking about this sidechain bug? It seems that I’m lucky again, because this bug only affect groups and I don’t use groups. Anyway, this should be fixed of course, no doubt.
The free version isn’t that good, but the chargeable version is quite good. I’m using it all the time. Good for anything in terms of registry issues, driver updates, performance issues, deinstallations, cleanings and so on.