[Lynn]

FIXED:

How I resolved the issue:

PHP код:

CMD:somecmd(playerid, params[])
{
    if(somevariable == true)
    {
         //Do some stuff
    }
    else
    {
        SendClientMessage(playerid, -1, "Error Message);
    }
    return 1;
} 


Changed to:

PHP код:

CMD:somecmd(playerid, params[])
{
    if(somevariable == true)
    {
         //Do some stuff
    }
    else
    {
        SendClientMessage(playerid, -1, "Error Message);
        return 1;
    }
    return 1;
} 


Conclusion:

Commands didn't work due to a missing return value.
Don't forget to return values in your commands!