[ZASTRELIS]

Not found any solve for this problem. But I understand that it often happens at warmup round, so.. -nobots + fix

public OnPluginStart()
{
    AddCommandListener(Command_JoinTeam, "jointeam");
}

public Action Command_JoinTeam(int client, const char[] command, int argc)
{
    if(!IsValidated(client) || (argc < 1))
    {
        return Plugin_Stop;
    }
    
    if(GameRules_GetProp("m_bWarmupPeriod") && GetClientTeam(client) >= 2)
    {
        PrintToConsole(client, "Spawn Blocked!");
        return Plugin_Stop;
    }
    
    ...
}