Fixing Client Sort Mod When the Middle Mouse Button Does Nothing

Check the Keybind First

The most common reason sorting fails is that the sort action is bound to a key your setup does not send. Open the controls/keybinds screen and find the Client Sort entry. If it is set to the middle mouse button, confirm your mouse actually registers a middle click — some mice lack a clickable wheel, and some drivers remap it. Rebind the sort action to a keyboard key you can press comfortably while hovering a container.

Confirm You Are Hovering Slots

Client Sort only acts on the slot grid under your cursor. If your pointer is over the crafting output, the search bar of a modded container, or the empty margin of the GUI, the keypress will not sort anything. Move the cursor so it sits directly on top of the slots you want reordered, then press the key.

Look for Conflicts

Other inventory or mouse mods can claim the same button. If a different mod opens a menu or does something else when you middle-click, that mod is intercepting the input. Resolve it by assigning Client Sort a unique key, or by changing the other mod's binding.

Test in a Safe Container

To isolate the problem, place a chest, put a few unrelated items in it, and try sorting with each modifier. If plain sorting works but a modifier does not, the issue is a key conflict on that modifier rather than the mod itself. If nothing works in any container, revisit the keybind step.