So I added a Cubase plug in to my mastering chain and it showed up with a red background. I deactivated everything in the chain except for this one plug in (Magneto II). No change. I added it with the drop down list - no change. I added it by dragging and dropping - no change. Any idea what might be going on? A Cubase restart did not fix it.
SOLVED. I had no idea that the green divider above the plug in was moveable and set how many pre-fader inserts you could have. I suppose I should RTFM! Haha.