If you are using Google Voice, here is the fix.
1. Go to Google Voice and deactivate the Google Voice
2. Log into your Version voicemail and listen to and delete any messages.
3. Go back to Google Voice and activate Google Voice
The reason the notification happened is that a voicemail was mistakenly directed to your Verizon voicemail instead of Google. Various things can cause that of which you have no control.
The above will remedy the situation.
Note that activating and deactivating will not affect your Google voice number.
When deactivating, be patient and follow the instructions. It is simple. They will give a code to dial on your phone (e.g *73) Yo enter the code as if you are dialing a call. You dial the call and just wait until it makes the call and then automatically hangs up. You have to wait for it to hand up. Don't hang up on your own.
Once it is deactivated, you can then access your Verizon voicemail to delter the errant voicemail there. Hopefully you remember your Verizon voicemail password.
Activating your Google Vociemail again is similar to deactivating except that you will have a longer code to enter.