A BI developer called me with the above error. Screen sharing suggested he is getting the error with the following option:
Overwrite the dataset
Clicks Deploy (to SharePoint)
Error 1 Report Server has encountered a SharePoint error. —> Microsoft.ReportingServices.Diagnostics.Utilities.SharePointException: Report Server has encountered a SharePoint error. —> Microsoft.SharePoint.SPException: User cannot be found.
Tried various things like checking his permission to SharePoint. He had full permission. Then we tried to rename the report and repost and that did not help.
Finally the developer himself figured out that he had to open Visual Studio with admin rights (run as Administrator) before trying to deploy. That resolved the problem.