I'm currently using Minecraft 1.52 with Forge version 7.8.0.690. Clean install, no mods, except forge itself. No texture pack running nor non-default graphics settings.
When dragging an item in the inventory and releasing it improperly, say, for example, releasing it onto the gray field near the crafting box, the item snaps back to its original position(as it should), and then the game immediately crashes.
I have been getting this ever since the first forge update for 1.52. I have removed all mods, except for forge, and it still happens. In a completely clean install of 1.52, it does not happen. This is very specifically a problem with forge.
I have a few dozen error logs, I shall include only the newest one at this time, as it is the absolutely clean install of 1.52+7.8.0.690, with no other mods involved.
