[Kindred]

Try something like this:

pawn Код:

new GotoDisabled[MAX_PLAYERS];

public OnPlayerConnect(playerid)
{
    GotoDisabled[playerid] = 0;
    //Rest of code for OnPlayerConnect
    return 1;
}

CMD:goff(playerid, params[])
{
    if(IsPlayerConnected(playerid))
    {
        if(GotoDisabled[playerid] == 1) return GotoDisabled[playerid] = 0;
        else return GotoDisabled[playerid] = 0;
    }
    return 1;
}

CMD:go(playerid, params[])
{
    new ID;//creates a new something idk what we call it :P but it is defined later on or used in something this 1 is used in next line
    if(sscanf(params, "u", ID)) SendClientMessage(playerid, 0xFF0000FF, "USAGE: /goto [id]");//checks if you have written something after /goto if no it sends error
    else if(!IsPlayerConnected(ID) || ID == playerid) return SendClientMessage(playerid, 0xFF0000FF, "This player is offline or it is yourself"); <--------------This is the error line.
    if(GotoDisabled[ID] == 1)
    {
        new string[50], name[MAX_PLAYER_NAME];
        format(string, sizeof(string), "%s's goto is disabled!", GetPlayerName(playerid, name, sizeof(name)));
        GameTextForPlayer(playerid,string,2000,3);
        return 1;
    }
    else//ELSE what will happen if no errors
    {
        new Float:x, Float:y, Float:z;//creates new floats
        GetPlayerPos(ID, x, y, z);//gets the player id(which we have entered after /goto position and like saves them into x,y,z defined above as floats
        SetPlayerPos(playerid, x+1, y+1, z);//sets the player position the id of that player +1 in x +1 in y and z remains same as it defines height
    }
    return 1;
}

Should work with no errors.

Hope I helped.