[Claude]

That is still long, make it on this way;

pawn Код:

public OnPlayerUpdate(playerid)
{
   // other things
   if(GetPlayerSkin(playerid) == 0)) SetPlayerSkin(playerid, 1);
}

Else add brackets after if(GetPlayerSkin(playerid) == 0)) and after SetPlayerSkin(playerid, 1);