In order to fix the problems, I recommend you uninstall the software (Control Panel > Uninstall a program) and run a registry cleaner. After that, reboot the computer, install the utility again and try to edit the videos. If the issue persists, you will need to contact the official developers and ask for help. You can get in touch with them using the Support page. Also, you can try using other video editors from Software Informer database.