"And the vendor wouldn't sell you the Unassembled GEMINI Belt token? The game, unfortunately, has a bugged display in vendors whose prices are "X of this and Y of that". It shows both X and Y in red unless you have enough of both. What it should do is what GW2 does: show the "not enough" number in red and the "you have enough of this one" number in green. So if you don't have enough UCs but you do have the gear piece, the vendor currently shows the gear piece in red AND the required number of UCs in red, while it should show the gear piece in green and the UCs in red."
I have over 2k Unassembled Components on this toon and the belt to boot. But it will not allow me to upgrade. I have gone to all 4 t4 vendors just to see if they would give me the upgrade...nope.
I have the same issue on my sorc. Item rating 242 [iokath MK-5 Relic of Focused Retribution [Augmented]] and can not upgrade the relic. I ended up getting another belt on my operative (exact same belt) and was then able to upgrade. I'm lost. I've submitted tickets on it in the past but got nowhere.