By default, the FME Server Windows Service is set to use the local system account, which does not have network permissions.
If FME Server requires access to network directories to read or write data, or if you use UNC paths to specify a remote repository or upload directory location, you might need to run the FME Server Windows Services with a different account.
Select Start > Control Panel > Administrative Tools > Services.
or
Run services.msc to open the Windows Services panel.
In the Services list, right-click FMEServer service, and select Properties from the context menu.
Select This account, and enter a user account and password that provides the required network permissions to the FMEServer service.