Replace ExecuteHamB... with this :
PHP Code:
set_pev(id, pev_deadflag, DEAD_RESPAWNABLE)
dllfunc(DLLFunc_Think, id)
Not sure 100% but you may try.
And add condition to userkill:
PHP Code:
if(is_user_alive(id))
user_silentkill(id)
Maybe the error is caused by user_silentkill code which is executed on already dead player, i dont know , just make it safe and test.