Issue while configuring the report server to run under a domain account.

I am getting issue while configuring report in integrated mode! The issue and the solution to that is as mentioned  here.

I tried to set the Report Server Service account to Use Another Accountbut when i try to apply i get the issue as below.

Microsoft.ReportingServices.WmiProvider.WMIProviderException: An unknown error has occurred in the WMI Provider. Error Code 800708AC

 ---> System.Runtime.InteropServices.COMException (0x800708AC): The group name could not be found. (Exception from HRESULT: 0x800708AC)
   --- End of inner exception stack trace ---
   at Microsoft.ReportingServices.WmiProvider.RSWmiAdmin.ThrowOnError(ManagementBaseObject mo)
   at Microsoft.ReportingServices.WmiProvider.RSWmiAdmin.SetWindowsServiceIdentity(String accountName, String password, Boolean useBuiltinAccount)
   at ReportServicesConfigUI.WMIProvider.RSReportServerAdmin.SetWindowsServiceIdentity(String accountName, String password, Boolean useBuiltinAccount)

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Kindly help!