You can try resetting VP to all the original default settings. Hold down the CTRL + SHIFT keys at the same time and click the program icon to start the program (the executable file that you would use to start the program). A pop-up dialog asks, "Do you want to reset all Vegas Pro preferences to default values" and "Delete all Cached Application Data" ..Click Yes.. This will restore the program to factory default settings.--
If that does not help, Uninstall VP using a third-party uninstaller like Revo Uninstall, which has the option to clean the old VP registry entries, system files, folders and other garbage the default Win uninstaller leaves behind. Then reinstall.