OK, so I downloaded the trial version of Vegas Edit 20, just to see if there no horrible bugs, all good until I tried Primate studio that's on my system from V19.
Q. Can I use older plugins inside my latest version of VEGAS Pro 19?
At this time, we only support the latest version of Continuum for VEGAS Pro 19. Customers who have upgraded and have older licenses of Boris Continuum plugins should contact sales for more information on upgrading.
Presumably the same approach applies to Vegas Pro 20. But I am certain that for years many on the forum have successfully used BCC plugins that accompanied previous Vegas Pro versions in their latest Vegas Pro version.
Try reinstalling Primatte Studio as doing so might update access in Vegas Pro 20.
However, one proviso: if you have any other BCC plugins installed, ALL of those BCC plugins MUST be from the same version. See this from BorisFX's FAQs:
Q. I had some older Boris plugins that disappeared. What happened?
Only one version of Boris FX Continuum plugins can be installed for VEGAS Pro at any one time. So, if you have an older version of VEGAS with legacy Continuum plugins, these will be replaced with the newer versions that ship with VEGAS Pro 19. We highly recommend uninstalling any existing Boris FX plugins previously installed on your system to avoid problems. To do this, right-click the Start button and click Control Panel. Go to Programs and Features (if your Control Panel is in Category view, go to Uninstall a Program). Find Boris FX Continuum, click to select it, and then click Uninstall.
However, if you want to keep your older Boris FX plugins, then you do not install these current products as they will overwrite any older plugins.
There was an update for Continuum that would not crash Vegas 20, but it was for Continuum 2022. If your version of Primate isn't that, you might have to contact Boris. But even the fix for Continuum isn't a fix. Vegas is aware of the problem and is working with Boris to fix it.
Interesting, thought I would check out VP20 just to make shaw it worked without issues with the intention to buy. It doesn't have much more for me than VP 19, but thought why not support the developer's. But maybe I will wait for a while and see if they can get to the bottom of the problem.