Veeam error when MCNAUGHTON\Administrator credentials are changed

If you change the password on the MCNAUGHTON\Administrator account, you will get the following error from Veeam when trying to backup:

Error    RPC function call failed. Function name: [IsSnapshotInProgress]. Target machine: [xxx.xx.x.xx].

To fix this, open Veeam and go to Backup Infrastructure > Managed Servers > Microsoft Hyper-V > Excelsa > Properties. 

Then click on "Credentials" and "Manage Accounts."  

You will need to change the password for the MCNAUGHTON\Administrator account.  After you change the password, the backups should run normally again.