If you think it's related to the toolbar, I would try backing up your configuration, then doing a clean install and seeing if the problem still happens with a default configuration.
To do that, open the Preferences dialog and use File -> Backup & Restore from its menus. Save the config backup somewhere save.
Then uninstall Opus via the usual Control Panel (it's under GP Software in the list), reboot, and install Opus again.
You can then see if the problem is still there with the default config, and then re-import your config via the same menu that was used to back it up.
If the problem turns out not to be related to your config, then the Crash, exit or high CPU when viewing certain directories guide has things to try next in order to narrow down the cause.