Well, I took down the array and removed my second cache drive only leaving my 1 250gb SSD instead of my 120 and 250 and the docker installed right away ¯\_(?)_/¯ .
That tool didn't really help much although I did put the new shutdown plugin on so +1 for that.
Anyway, the other drive I took out works fine and is actually part of my raid array now :-/. No Idea what is actually wrong, maybe its an issue with the Beta version with multiple different sized cache drives.