Console spam/Lag/Timeout

So, after some time of joining a server my console starts getting spammed with WEAPON:SetWeaponHoldType. Then, I start lagging a LOT but I can still hear players talk fine. And finally, my connection to server times out. Any help?

That error is a problem of the servers themselves.
In the latest GMod update they changed the SetWeaponHoldType function to SetHoldType.

Servers that have custom weapons, should update their weapon’s files to reflect that change.
I myself have not had the issue where it actually times out connections of anyone in my server, before I fixed this myself.
There might be another cause to your disconnects. That I cannot say with full certainty.

EDIT: Unless you are actually using a weapon pack on your own game that is also used while being on the server(s), in which case you’d have to update or fix those files yourself… But that seems illogical to me.