Do you have dopus.exe launched elevated (the whole process, not just using Admin Mode after launching it normally)? That will break the ability for non-elevated processes to ask it to open new windows.
Failing either of those, and if the problem still exists after rebooting, I would suspect antivirus or something blocking the process from launching.
Whatever is messing up your window titlebars and drawing icons all over the text of them could be involved as well, perhaps.
The title buttons are from Actual Windows Manager, I do not think it should interfere, as I have had it for years.
Opus is located in
C:\Program Files\GPSoftware\Directory Opus\dopus.exe
and is set to run as administrator: