What were you doing when it happened? Did the plugin run fine before and suddenly crash, was this during loading, ...? Does it reproduce?
The plugin was crashing inside the host consistently before that final hang, but I couldn't narrow down what was doing it. I had one instance per track (4 tracks with various bass and EQ effects) and one on the master bus (clipping), and I couldn't tell which one was the culprit when it hung.
However before the hang, it would be playing, I would close the window, switch to a new track, start adjusting parameters in ST for it, then suddenly a track I wasn't working on that very moment goes silent (presumed crashed plugin without a GUI to show the error). Removing or replacing the FX is the only way to return audio to the bus and get the GUI back, so that's a plugin crash, right?
I couldn't get it to reproduce with the 64 bit VTS3 once I got it working. I'll spend more time with the 32 bit VST2 today trying to reproduce it and catch it before it goes away.