The machine may need rebooting after updating Opus 11 to Opus 12, before the dopus.exe command can work. (This is true of minor updates as well, but you wouldn't need to run dopus.exe to install a new licence file for those.) Is that being done?
Also, has the silent install file been re-made with the new installer, or are you re-using the one from the Opus 11 installer?
If you can locate a crash dump file and email it to leo@gpsoft.com.au we might be able to tell what's causing the crash.
PS: Please do not post registration details to the forum. The entire world can read them.