I’m currently working on a project standing up 3 UAG servers in an array. I ran into a problem where the UAG array master couldn’t connect to one of the UAG array members.
It turned out for some oddball reason the computer account of the array master wasn’t added in the array member’s local administrator group. The screenshot below shows UAG02 on the left and UAG03 on the right. See how UAG3 is missing the array master’s computer account? This was strange because everything looked correct in TMG on UAG03. 
I added the array master’s computer account to the array member that was having the problem and all is well in the world now. 
See, I told you all is well in the world.
