Since I installed Catalina yesterday, I have had around five crashes with the error:
panic(cpu 6 caller 0xffffff7f8879cad5): userspace watchdog timeout: no successful checkins from com.apple.WindowServer in 140 seconds
Any solutions. iMac Pro had been operating fine before update. Only apps running at the time were Chrome and TimeMachine backing up to a Drobo 5N2 (plus of course background apps like Google Backup and Sync, Dropbox, etc).