I'm going to mark this as "resolved" but there's still something off with the VST3 scan.

Here's what I did...

1. Checked my old DAW build to see what the VST3 scan directories were. Renamed directory C:/Program Files/Common Files/VST3 so that it couldn't be found. Reran the VST3 search window in BiaB and it did not crash. But it did not find any VST3s either, naturally. However, I could now get past the prompt screen and access the VST3 search window Options.
2. Restored the VST3 directory name and removed VST3 files by manufacturer, one group at a time. Figured out it was one of the Wave shells that was the culprit.
3. With Waves plugins omitted, the only VSTis detected were the BiaB plugin and Sforzando.
4. Pointed the BiaB VST3 search to the directory with the Roland Sound Canvas VA 64-bit plugin and did a rescan, but it was not detected, which is weird because I'm sure I somehow had it loaded as the default synth yesterday.

So there are still some odd results in how the VST3 search prompts are behaving, and #4 above is a particular issue since my old DAW build, using the same BiaB build, detected and ran Sound Canvas VA perfectly. I'll start a new thread on that if necessary.

THANKS, Simon!!

DC Ron
BiaB Audiophile
Presonus Studio One
StudioCat DAW dual screen
Presonus Faderport 16
Too many guitars (is that a thing?)