Launching VP20 just now it seemed to freeze... I noticed "updater" was using high CPU and this traced back to the Vegas folder "VEGAS/VEGAS Pro 20.0/UPS" --using Task Mgr went to the details and that took me to "Service_rel_u_x64_vc16.exe"

I ended the service, then ended the hung V20 launch (via task mgr). Then re-launched Vegas.. hung after drawing a few windows. Killed again. Noting a high-ish CPU on a local SQL Server process (QB uses it I think) I ended QB... then Vegas loaded OK.

Anyone else experience oddities like this? I'm thinking a reboot may be in order... but thought I'd check in here anyway.

Didn't noticed the high cpu usage but i have the same error as you,

Nom de l’application défaillante Service_rel_u_x64_vc16.exe, version : 5.15.38.34, horodatage : 0x64bfddd6
Nom du module défaillant : Qt5CoreMx64Qt5.15.1.dll, version : 5.15.1.0, horodatage : 0x5f74976c

i'm afraid I need to contact support (where ? ) for this. did you fixed this issue ? i'm getting this error in Vegas Pro 21, never got in Pro 19 (I didn't upgraded to 20) so i assume it's related to the new code done for 20/21.