DR 17 Freeze instantly after hit play *SOLVED*

Just installing the release of DR17 on MacPro/VegaDuo on latest BigSur. Also VideoDesktop is up to date. Startup works fine. But after hit play, DR freezes instantly and can't quit anymore (force quit only). Also the integrated color bars don't play.

Edit: After more tests it seems the Decklinck 4K extreme 12G (quad SDI) is the problem. If I disable the card playback works fine.

Any ideas why?

Thanks very much,
Dany

[Peter Chamberlain]

What specific Desktop video driver is installed?
'Latest' doesn't help convey any info.

[Dwaine Maggart]

Did the issue occur at the same time as a Big Sur update, i.e. updating from Catalina or Mojave to Big Sur, not a Big Sur point update?

Did the issue occur at the same time as a Big Sur update, i.e. updating from Catalina or Mojave to Big Sur, not a Big Sur point update?

Updated from Catalina to Big Sur a few months ago. But the issue was the gatekeeper that not allow install DV12.0 correct.