You may be seeing an error message similar to this when running Hero on multiple processors on a Windows computer:
Unable to open the HKEY_LOCAL_MACHINE\SOFTWARE\MPICH\SMPD\process\62600 registry key, error 5, Access is denied.
Hero uses the MPICH2 implementation of the Message Passing Interface (MPI) standard. This error message is produced with the SMPD service, which enables parallel processing, is unable to access/update a registry key in Windows. This error is likely caused by having reduced user privileges on your computer. This error may safely be ignored, and your Hero job should run without any issues.