Question : SQL Errors - Cannot execute as the database principal

We've enabled SQL notifications on our databases, and recently upgraded out servers. Hence backing up and restoring the databases to the new server. In doing this, we now generate massive logs with the following errors (about 10 a second).

The activated proc [dbo].[SqlQueryNotificationStoredProcedure-92722d2e-21fc-40b9-8398-63b89cafb97a] running on queue DATABASENAME.dbo.SqlQueryNotificationService-92722d2e-21fc-40b9-8398-63b89cafb97a output the following:  'Cannot execute as the database principal because the principal "dbo" does not exist, this type of principal cannot be impersonated, or you do not have permission.'

Running select name,suser_sname(owner_sid) as owner from sys.databases; shows a login of sa for some databases (no errors, no notifications set up in here) and domain\username for the databases we have errors with.

Running USE DATABAENAME GO sp_changedbowner 'sa'; or with 'domain\user' causes the following error: Cannot find the principal 'domain\user', because it does not exist or you do not have permission.

Any ideas how to fix these? It's filling up our HDD space quite quickly.

Thanks.

Answer : SQL Errors - Cannot execute as the database principal

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