The message pops-up when following the instructions available in BMR_best_practices.pdf document, when attempting to start the services called 'Server' and 'Remote Registry'.
There are registry entries that must be loaded first on the target BMR computer, otherwise the services 'Server' and 'Remote Registry' cannot be started in safe mode.
Enable the required services on the BMR target computer (started in Safe Mode with Networking) by creating a file with the content below (you can use Notepad and create it as a text file first, then change its extension to .reg, and then double-click on it to have its content loaded in registry, there will be a Windows information message confirming that the content was successfully loaded):
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\RemoteRegistry] @="Service" [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\SamSs] @="Service" [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\Schedule] @="Service" [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\srv] @="Driver" [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\srv2] @="Driver" [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\srvnet] @="Driver"