Knife attack doesn't have force

[AdamTadeusz]

from CBaseEntity::VPhysicsTakeDamage

// If you hit this assert, you've called TakeDamage with a damage type that requires a physics damage
// force & position without specifying one or both of them. Decide whether your damage that's causing
// this is something you believe should impart physics force on the receiver. If it is, you need to
// setup the damage force & position inside the CTakeDamageInfo (Utility functions for this are in
// takedamageinfo.cpp. If you think the damage shouldn't cause force (unlikely!) then you can set the
// damage type to DMG_GENERIC, or | DMG_CRUSH if you need to preserve the damage type for purposes of HUD display.
#if !defined( TF_DLL )
Assert( force != vec3_origin && offset != vec3_origin ); <-- Failed assert when attacking a prop (like the lanterns on nt_dawn_ctg) with knife