Not able to delete SQL Server Maintenance Plan and/or SQL Server Agent jobs (4220813)

You may get below error while trying to delete Maintenance Plan after server name change: -

TITLE: Microsoft SQL Server Management Studio
Exception has been thrown by the target of an invocation. (mscorlib)
ADDITIONAL INFORMATION:
An error was encountered when trying to remove the package “Maintenance Plans\MP_name” from SQL Server.

and/or

You may get below error while trying to delete SQL Server agent job (after deleting the LiteSpeed Maintenance Plan): -

TITLE: Microsoft SQL Server Management Studio
Drop failed for Job ‘UserDB_Tlog.Subplan_3′. (Microsoft.SqlServer.Smo)
ADDITIONAL INFORMATION:
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
The DELETE statement conflicted with the REFERENCE constraint “FK_subplan_job_id”. The conflict occurred in database “msdb”, table “dbo.sysmaintplan_subplans”, column ‘job_id’.
The DELETE statement conflicted with the REFERENCE constraint “FK_subplan_schedule_id”. The conflict occurred in database “msdb”, table “dbo.sysmaintplan_subplans”, column ‘schedule_id’.
The statement has been terminated.
The statement has been terminated. (Microsoft SQL Server, Error: 547)

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The SQL Server host name has been changed.

WORKAROUND:
Manually delete the entries from system tables in msdb database, using the following queriesm then connect to integration services on this server and manually delete the package under msdb.
 

select * from sysjobs -- to find the correct jobid

select * from sysjobschedules where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

delete from [dbo].[sysjobschedules] where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

select plan_id from [dbo].[sysmaintplan_subplans] where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

select * from dbo.sysmaintplan_log where plan_id = '755708E5-5B24-4B31-8AC3-38944E6A99A3' -- planid is the value from above sql

delete from [dbo].[sysmaintplan_log] where plan_id = '755708E5-5B24-4B31-8AC3-38944E6A99A3' -- planid is the value frm above sql

select * from [dbo].[sysmaintplan_subplans] where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

delete from [dbo].[sysmaintplan_subplans] where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

delete from sysjobs where job_id ='B0C44798-7ABC-456B-B819-C369CE80150C' -- update job_id with your job id number

Note: This solution is from http://databasebestpractices.com/delete-sql-server-maintenance-plan-andor-sql-server-agent-jobs/