Running dspMixFx to control my UR-RT2, if I open any of the Yamaha Guitar Amp Classics FX, the window comes up, but the window doesn’t update, i.e., is frozen. Interestingly, the controls still work, responding to your mouse click/drag.
Oh, btw, the design aesthetic of the UR-RT2 software, inc. dspMixFx, the Cubase MixConsole Hardware routing panel, the Rev-X window, and any I forgot, is really, really bad. It looks totally out of place - like something from the 1990s. Maybe you’re redoing all the windows??