Issue with ingame menu

[rikjahart]

Hi guys, sorry to bother, perhaps with a stupid question.
I just reinstalled Skyrim after a couple of years hiatus, and found an annoying issue right away.

There is a big square menu on the upper right side of the screen and I don´t know wich mode generates it.

Please if somebody can help me, I´ll apreciate it.

 

Thank you.