Installed AddOn: Pitbull 4.0 - N/A on WoWI, downloaded from WoWAce/Curse
Detected AddOn: Kollektiv Unit Frames - ID 11171 (?) (Also linked for your convenience) Properly displayed Pitbull 4.0 but installed kUnits when updated.
I only use two AddOns that aren't on WoWI, and I manually updated the second. It seems (from what's already been posted), that Pitbull 4.0 is pulling multiple different AddOns from WoWI.