The File Replication Service could not grant an unknown user access to the API "%1". Access checks can be disabled for "%1" ...

The File Replication Service could not grant an unknown user access to the API "%1". 
 
Access checks can be disabled for "%1" by running regedt32. 
 
Click on Start, Run, and type regedt32. 
 
Click on the window entitled HKEY_LOCAL_MACHINE. Double click on SYSTEM, CurrentControlSet, Services, NtFrs, Parameters, Access Checks, "%1", and "%2". Change the string to Disabled. 
 
Permissions can be changed by highlighting "%1" and then clicking on the toolbar option Security and then Permissions...