[TheArcher]

As MP2 said, it might be an include bug. However paste this and watch if the callback is working.

pawn Код:

public OnPlayerHeadshot(issuerid,playerid,weaponid)
{
    new temp_gun = GetPlayerWeapon(playerid);
    if(temp_gun == 34 || temp_gun == 23) // 34 is the sniper ID
    {
        SetPlayerHealth(issuerid, 0.0);
        printf(" player %d has been shot by player %d" , playerid, issuerid);
    }
    print(" Callback OnPlayerHeadshot has been called 2");
    return 1;
}