Since the newest patch me and some - but not all - of my friends cant change quickslot items.

Opening inventory, then going to "Quickslots" produces an empty screen, so the items already in quickslot can not be replaced. Tho, using the quickslot-wheel is possible.

For me it happens with all characters, no matter if with addons or without any addons. Several reloads, game restarts, etc. didnt solve the problem.