RPC errors when using certain workflows, e.g.
Error : The remote procedure call failed. (Exception from HRESULT 0x800706BE)
System Events report showed the following error
DAL Handled Exception, Desc:Get, Number DAL COM catch handler
Function : Get, catch handler. Error
IDispatch error #3092
SQL server encountered error 0x80077042d while communicating with full-text filter daemon host (FDHost) process. Make sure that the FDHost process is running. To re-start the FDHost process, run the sp_fulltext_service ‘restart_all_fdhosts’ command or restart the SQL server instance.
Where issuances seemed to be occurring fine some workflows were failing the RPC errors. Notably “Unlock Credential” and “Cancel Credential”. These were accompanied by RPC errors in the Audit.
The problem was down to the SQL Full Text daemon launcher service not running on the SQL server.
Starting the SQL Full-Text Filter Daemon Launcher service resolved the problems.