Maintenance Plans Failing Invalid Class String

This is on a SQL Server 2017. We are required to use maintenance plans for full/log backups and DBCC Checks. They have been working fine, but I received an email that they have failed yesterday. I see all jobs not based on maintenance plans are fine, but all jobs based from a maintenance plan fail. They are set for the SA account as owner and running as SQL Server Agent. Service accounts are running and accounts have permissions as I can run them manually just fine. Wrote to a output log for more details: >Started: 12:00:01 PM > >Could not load package "Maintenance Plans\Log" because of error 0x800401F3. > >Description: Invalid class string\ Source: \ Started: 12:00:01 PM\ Finished: 12:00:01 PM\ Elapsed: 0.219 seconds\ > >Microsoft (R) SQL Server Execute Package Utility\ Version 14.0.3465.1 for 64-bit\ > >Copyright (C) 2017 Microsoft. All rights reserved.\ I did install SSMS 20 yesterday, but then re-installed SSMS 19 and still have the issue. I'm not sure if it's related. I updated SSMS to 20 on many other database servers without any problems, but those were running SQL Server 2019. I'm not finding much on the web. Has anyone seen this before? Thanks