DCS 6.7 Trying to register NSX Manager, errors.

Trying to set up Integration in DCS management console and I get the following error:

"Failed to register the vCenter Server and NSX Manager with the management server 'Unable to register with NSX'.  Check the management server logs for details."

I can't seem to find this log file it says I should check so I'm a little stuck on how to proceed.

vCenter is version 5.5 and NSX version is 6.3.1, DCS version 6.7.2.7