Apex missing DOS Module

[14 foot reef]

Apex missing DOS Module can't seem to re link it lights blinking orange on DOS unit.
I tried leaving it unplugged, both the AC and Aquabus cable. Also unplugged apex and plugged back in. Still nothing. Any ideas would bee greatly appreciated.

 

[14 foot reef]

Idiot user error aquabus cable not plugged all the way in.