new countdowntimer;
new count = 11;

public OnPlayerCommandText(playerid, cmdtext[])
{
    if(!strcmp(cmdtext, "/start", true))
    {
        if(isclanwarstarted == 0)
        {
            new string[128];
            format(string, sizeof(string), "** Prepare yourself, a round is about to start!");
            SendClientMessageToAll(COLOR_MESSAGE, string);
            SetTimer("startcw", 5000, false);
            isclanwarstarted = 1;
            for(new i = 0; i < MAX_PLAYERS; i++)
            {
                PlayerPlaySound(i, 1139, 0.0, 0.0, 0.0);
            }
        }
        else
        {
            SendClientMessage(playerid, COLOR_ERROR, "ERROR: A round is currently running active!");
            PlayerPlaySound(playerid, 1053, 0.0, 0.0, 0.0);
        }
        return 1;
    }
    return 0; // filterscript
}




forward startcw(); // removed i since it's not needed in any way plus you cannot pass vars via SetTimer, only SetTimerEx
public startcw()
{
    // removed if(IsPlayerConnected(i)) it has to be inside the loop not here
    for(new i=0; i<MAX_PLAYERS; i++)
    {
        // Look the following two lines are so important when you use for loops to loop through players
        if(!IsPlayerConnected(i) || IsPlayerNPC(i)) // if i is not connected or is a npc
            continue; // skip and won't execute the following codes (No need to execute them since i is not connected at all or is a npc)

        // here i is a connected player and not a npc so do your codes
        if(gTeam[i] == TEAM_HOME || gTeam[i] == TEAM_AWAY)
        {
            /*
            count = 11;
            countdowntimer = SetTimer("Countdown", 1000, true);

            //I took those ^ 2 lines out of here and added them outside the loop.
            // If you want to know why read Nero_3D's post

            */
            iDM[i] = 0;
            First[i] = 0;
            ResetPlayerWeapons(i);
            SetPlayerInterior(i, 10);
            GivePlayerWeapon(i, 31, 9999);
            GivePlayerWeapon(i, 27, 9999);
            GivePlayerWeapon(i, 24, 9999);
            SetPlayerHealth(i, 100);
            SetPlayerArmour(i, 100);
            TogglePlayerControllable(i,0);

            if(gTeam[i] == TEAM_HOME)
            {
                SetPlayerPos(i, -1131.9910,1057.6470,1346.4126);
                SetPlayerFacingAngle(i, 270);
            }
            else if(gTeam[i] == TEAM_AWAY)
            {
                SetPlayerPos(i, -973.9210,1061.2968,1345.6729);
                SetPlayerFacingAngle(i, 90);
            }
        }
    }
    // Here they are
    count = 11;
    countdowntimer = SetTimer("Countdown", 1000, true);
    return 1;
}

forward Countdown();
public Countdown()
{
    new str[128];
    count--;
    if(count < 1)
    {
        for(new i=0; i<MAX_PLAYERS;++i)
        {
            if(IsPlayerConnected(i))
            {
                KillTimer(countdowntimer);
                GameTextForPlayer(i,"~g~~h~GO!",1000,3);
                PlayerPlaySound(i, 1057, 0, 0, 0);
                TogglePlayerControllable(i, 1);
                if(gTeam[i] == TEAM_HOME)
                {
                    SendClientMessage(i, TEAM_HOME_COLOR, "** The round has been started, good luck!");
                }
                else if(gTeam[i] == TEAM_AWAY)
                {
                    SendClientMessage(i, TEAM_AWAY_COLOR, "** The round has been started, good luck!");
                }
            }
        }
        return 1;
    }
    format(str, sizeof str, "~r~Round Begins in: ~h~~h~~h~%d", count);
    for(new i=0; i<MAX_PLAYERS;++i)
    {
        GameTextForPlayer(i,str,1000,3);
        PlayerPlaySound(i, 1056, 0, 0, 0);
    }
    return 1;
}