Norton is known to cause issues with various applications. You have to start the application then go to its configuration settings. Access Exclusion list and add the folder of YTD. Additionally you can add YTD's main executable file to that list. This way the antivirus will avoid scanning or checking the software. If I am correct, Norton detects YTD as malware/adware and deletes various components that are required. Re-install YTD and it should work normally.
TIP: Avoid installing other applications during the installation of YTD. Choose Decline or Custom and uncheck all the options.