The following custom weapons will cause your player to not be able to move or be affected by knockback
Scout
Secondary: USP match
Soldier
Primary: Quickhand
Secondary: Loose screw
Pyro
Secondary: Loose screw
Melee: Crowbar, Engi's Assistant, Stunstick
Demo
Primary: Demo shotgun, Iron boots
Melee: crowbar, stunstick
Heavy
Secondary: Annabelle, shortstop, loose screw
Melee:stunstick
Engineer
Primary: loose screw, annabelle
Secondary: USP match, fast fix
Medic
melee: stunstick, engi's assistant, syringe, stunstick
Sniper
Secondary: wepon
Melee: crowbar, stunstick