yea this has been an issue for a while now from the looks of a quick google search: https://www.google.com/#q=match+history+blank
from the chrome console i found out that the I18n.js file on one (or some) of the na servers have nothing after Line 7 column/char 376329. When i load the euw page i get the whole file. idk if this helps or not but im on the east coast. it seemed to me as if match history is working for people in other regions but im not too sure on that.
i wrote up a nice (detailed) report on this yesterday but then I got the 404 page when i clicked post. I kind of raged quit and went to bed after that lol.