If you're able to access the menus and do a configuration backup (Settings / Backup & Restore), it might be worth then uninstalling Opus and then reinstalling it, to see if the problem still happens with a default config.
Note that uninstalling will wipe your configuration, which is why you'll probably want to make a backup first (unless you've only made simple changes you don't mind losing).
If you can't access the menus due to the problem, it's possible to manually back up the config by copying the /dopusdata and /dopusglobaldata folders to a safe place (e.g. to your desktop, outside the folder they are in). Information on finding the folders is here.