The error occurs recently when one of our client migrated their VMs. Users were unable to open SharePoint Sites. After support ticket, when we checked the SharePoint Server and browse the SharePoint sites or Central Administrator, page was blank/404 error. At first, I reset IIS and restart the server. However, no luck :(. Secondly, I checked services, databases and server and found all are in … Continue reading Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401)