Its really weird to see Access Denied error for System Administrator in CRM.
When trying to open any record from Plugin trace logs, system throws the below error in our dev environment.
Access Is Denied
You do not have enough privileges to access the Microsoft Dynamics CRM object or perform the requested operation. For more information, contact your Microsoft Dynamics CRM administrator.
Unable to verify the missing access rights as there is no 'Download Log' button, platform trace cannot be checked since this is CRM online. I don't see any relationship control issue like lookup/subgrid in this OOB entity.
Also if you see the page title, it says Dashboard - fishy? Any pointers to troubleshoot this?