Windows Process Activation Service (WAS) was unable to notify protocol %2 about an identity change for application pool %1. ...

Windows Process Activation Service (WAS) was unable to notify protocol %2 about an identity change for application pool %1. This may prevent the worker process or processes in the application pool from processing requests for this protocol. To resolve this issue, change the worker process identity to a new identity and then change it back to the previous identity.  The data field contains the error number.