1. the weapon that was used (official or community made)

I can't tell which is causing it

2. list of addons, especially weapon packs

https://steamcommunity.com/sharedfiles/filedetails/?id=1317475965

3. steps to reproduce

It happens randomly, a gun doesn't trigger it, it just starts to happen immediately when someone joins.

4. Lua errors (if any)

[ERROR] lua/weapons/cw_base/cl_model.lua:1499: bad argument #2 to 'GetBonePosition' (number expected, got no value)
1. GetBonePosition - [C]:-1
2. unknown - lua/weapons/cw_base/cl_model.lua:1499

(Not sure if This is Related):

DataTable warning: (class player): Out-of-range value (-40.000000) in SendPropFloat 'm_flMaxspeed', clamping.