In attempt to fix this issue, please try the steps below:
Uninstall WavePad, then delete 3 folders named "WavePad" and 1 named "Components" from these locations:
**C:\Users\<username>\AppData\Roaming\NCH Software\WavePad\
**C:\Program Files (x86)\NCH Software\WavePad\
**C:\Program Files (x86)\NCH Software\Components
**C:\ProgramData\NCH Software\WavePad\
**If you can't find any of the folders, just continue.
After that, restart your computer and try again to see if the issue persists. If you still have problems, you can submit a support ticket: https://www.nch.com.au/support/