CAN'T DRAG CHAMPS OR ITEMS (UNPLAYABLE)

So here's the thing lol... I literally can't drag any items OR champions onto the field. When I try nothing happens and the blue hexagons on the field don't even show up. I've tried doing a client repair and reinstalling the game to no avail. Idk if this is common, but the bug basically makes the game unplayable as you can't move any champions around AT ALL nor can you drag items to apply on champs.