[Cell_]

From the data you have provided, I am guessing victimid is out of bounds, i.e, < 0 or > MAX_PLAYERS, assuming the User array is sized MAX_PLAYERS. Will have to see the GetClosestPlayer function to make sure that's the case.
On the assumption that that is the case, perhaps you should have some sort of a check on victimid before implementing the rest of the code. Something like:

pawn Код:

if(victimid >= sizeof(Users) || victimid < 0) return 1;

Adding this to the after the new victimid = GetClosestPlayer(playerid,2.0) part of this code might help. I am also assuming this code is under OnPlayerKeyStateChange so playerid is not out of bound.

Making the final code look something like this:

pawn Код:

if(Team[playerid] == Zombies && User[playerid][USER_MINIJUE]==0 && User[playerid][USER_Evento] == 0 && User[playerid][USER_TipoD]==0 && newkeys & Morder) 
    { 
    if(GetPlayerWeapon(playerid) == 0) 
    { 
    new victimid = GetClosestPlayer(playerid,2.0); 
    
    if(victimid >= sizeof(Users) || victimid < 0) return 1; // can also replace sizeof(Users) with MAX_PLAYERS but you can only do this if your Users variable looks something like this Users[MAX_PLAYERS][someEnum]
    
    if(Team[victimid] != Zombies ) 
    { 
    if(IsPlayerPaused (victimid)) return GameTextForPlayer(playerid, "~G~El jugador se encuentra~N~ pausado", 6000, 4); 
    new Float: Health; 
    GetPlayerHealth(victimid, Health); 

    switch(User[playerid][USER_Mutacion]) { 
    case 0,2: { 
    if(Health <= 10 && User[victimid][USER_Muerto]== 0 )SendDeathMessage(playerid,victimid,WEAPON_DROWN),User[playerid][USER_KILLS]++,User[victimid][USER_Muerto]=1; 
    code. 
    . 
    . 
    . } 
    case 1: { 
    if(Health <= 20 && User[victimid][USER_Muerto]== 0 )SendDeathMessage(playerid,victimid,WEAPON_DROWN),User[playerid][USER_KILLS]++,User[victimid][USER_Muerto]=1; 
    code . 
    . 
    . 
    . } 
    } 
    SetPlayerScore(playerid,User[playerid][USER_SCORE]); 
    } 
    } 
    return 1; 
    }