The Windows Process Activation Service (WAS) encountered an error attempting to look up the built in IIS_IUSRS group. There ...

The Windows Process Activation Service (WAS) encountered an error attempting to look up the built in IIS_IUSRS group.  There may be problems in viewing and setting security permissions with the IIS_IUSRS group.  This happens if the machine has been joined and promoted to be a Domain Controller in a legacy domain.  Please see the online help for more information and solutions to this problem.  The data field contains the error number.