Please try downloading the current version from our website and then installing it over the top, without uninstalling. Reboot when prompted at the end of the install.
Another thing to try: Create an empty folder on your desktop, then right-click it and choose the option to open it in Opus. If that works, it could have been Opus was trying to open a folder with something inside it that caused it to crash.
If that doesn't work, doing an uninstall and then a re-install is worth a try. Uninstalling will wipe your configuration (which may be where the problem is), so if you do not already have a backup and want to keep it, you will want to manually back it up first. To locate the configuration folders, see Locating the config files by hand in the config backup faq.
If doing an uninstall & re-install, please try running Opus with the default config before restoring anything from your config backup.
Please also link your account for further assistance.