Here are some screenshots of an error I had recently.
I think I only had one instance of Poise loaded in my project and nothing more,
im not sure, but 100% no Grace there.
Poise was organized in group of tracks, includning 4 outputs. Three of them had an
instance of T-Rex Classic Compressor loaded.
The error occurred when I was changing presets of one of the compressors.
Before that, I did a lot knob-tweaking in Poise while playback playing, which seems
to me is one of the reasons of the problem (it slows my comp a lot). It's worh
mentioning because I had a similiar impression in case of the Grace bug I reported
on the Forum.