Users complain about reports are not opening and giving error "Unable to load Data Model". When we connect to the machine we checked Memory & CPU both were fine & we thought that there might be a Service issue so we restarted the service but receive the following error then we tried to change the service user to admin any applied changes in the Report Server configuration still we received the following error 

System.InvalidOperationException: Cannot start service PowerBIReportServer on computer 'Server'. ---> System.ComponentModel.Win32Exception: The service did not respond to the start or control request in a timely fashion

--- End of inner exception stack trace ---

at System.ServiceProcess.ServiceController.Start(String[] args)

at ReportServicesConfigUI.Panels.ConfigurationPanelWithErrors.StartOrStopServiceTask(Boolean start, String serviceName)​