here you go. backpack bug only works on some people, works on me, doesn't work on Panda, admin of AU Scourge and Wee Tu Lo, player of AU Scourge.
Will walk ya through it bc my voice a little low.
Step 1: Have backpack equipped.
Step 2: Click stack of items. (Worked for stone and fuel for me)
Step 3: Right click the number on the splitting bar.
Step 4: Input custom number.
Step 5: As soon as you click on the stone to drag your custom stack into your inventory, backpack spits out.
Step 6: Momentarily hate rust, and everything it stands for.
Step 7: Realize you can't pick backpack up. Admin also cannot place backpack on you, as it will spit it out.
Fix: F1 kill and log out, or open F1 console and type backpack false