Strange visual bug since update 6.1

[Eili]

Since this morning, i have a strange circle appearing on my screen each time i use the inventory, or receive a new item, or a new item quest.

As soon as i mouse over the new items in the inventory the circle vanish



I tried to click on it, to move it but there is nothing to detect it really.

Do you think it is something i could have forget in one of my previous update ? All the icons are invisible in my UI, could that be a new icone ? or a changed one ?

I am just lost because it goes off and on with mousing and i did nothing for that.

THank you for any answer