This might be the reason you have set up SQL Always On and an extra Job step has been added to the MSCRM_Config.SiteWideCleanup SQL Agent Job to add a check if it was running against a SQL server 2012. Could you please verify that and remove that extra job step first and then Apply the UR11 one applied successfully you may re-add the Job step. If that is not the case then please share the complete log when it is failing and we will share more information with you.
More information: The SQL 2012 Always On documentation for CRM 2011 has now released:
technet.microsoft.com/.../jj822357.aspx
Thanks,
