Try doing a clean install and delete all the cache of the program. Uninstall your software first, then go to the folder location below on your computer then delete the Disketch folders:
C:\ProgramData\NCH Software
C:\Users\(Your computer profile)\AppData\Roaming\NCH Software\Disketch
If you can't find the AppData folder, set Windows to show hidden files and folders with the steps from this link: https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files.
After deleting the Disketch folder, restart your computer then install it again from the next link: https://www.nchsoftware.com/cdlabeler/disketchpsetup.exe
That should do it. Please try it again after that and see if that fixes the issue. if you still getting issues, would be better to escalate this to the Technical Team