Hello all. I was experiencing the same issue on a single Windows 8.1 workstation on a domain. The station was visible in the cloud console, but it wouldn't show any info. I uninstalled/reinstalled MBEP, removed all traces of it in the registry and file system, and nothing helped. I also noticed that I was getting seemingly unrelated GroupPolicy EventID 1090 errors and was unable to view RSoP info, possibly due to WMI errors. As this was a legacy client that I inherited from a completely incompetent IT provider, I decided to reset some key items using Tweaking.com's Windows Repair to make sure all services were set to their defaults. So I ran the following repairs:
Reset Service Permissions
Repair WMI
Repair Hosts File
Remove Policies Set By Infections
Restore Important Windows Services
Set Windows Services to Default Startup
After repair and rebooting, I right-clicked on the MBEP icon in the System Tray and the "Start Threat Scan" message came up (I usually use this as a quick way to determine if it has initially synced with the cloud console and installed all components). I then checked the console and the station was there and all station info was now populated. Lastly, my Group Policy issues were also resolved. Now all i have to do is cancel my support ticket with MB.
Hopefully this helps.
Robert