Hello Nick!
If Vienna Ensemble Pro crashes and a crash report is generated, please send us this crash report. Then we can take a look at what might have gone wrong.
The keyword "unis" doesn't generate any sound ID with the "Vienna Symphonic Library" House Style loaded. If you want to switch back to unison playing after a divisi passage with Dimension Strings, please use "ord." and "tutti" (or "a2", "a3", "a4", ...).
A complex setup like yours that uses sound sets that include the same instruments (like VE Woodwinds+Brass and VE Special Edition or VE Strings and VE Special Edition) can sometimes bring up seemingly erratic behaviour. I didn't anylyse your playback configuration in every detail. Maybe you can make a playback configuration that only uses the sound sets VE Strings, VE Woodwinds+Brass and VE Percussion.
Best regards and happy Easter,
Andi