load & unload entities w. lua

[Combine]

Hey ahm as i have just a very small knowledge of lua coding... does anyone know whats the problem on this code?

I wanted too make a lua script that load/enable unload/disable hammer entities like a prop_dynamic with a specific name

why and for what do i need this script? well i always was amazed about how valve put multiple gamemodes in one map like they did on L4D

in the older source engine versions -> hl2 you cant do that as gmod for example has no info_gamemode where u can set a custom gamemode which can use in/outputs on entities

info_gamemode
(i know it exist in gmod but it doesnt work that well... and as i said you cant set custom gamemodes)

so i thought it is possible if you do it with a lua script so i put some stuff together and i think this here is the way how you can do it but for some reason if i set a prop like prop_dynamic disabled on start you cant enable it with this script is there a reason why? or is there someone who could do something about this?

// ------------------------------------------------------------------------------------------ //
if engine.ActiveGamemode() == "terrortown" then

    for _,ent in ipairs(ents.FindByName("TTT")) do
        ent:SetKeyValue( "StartDisabled", "0")
    end
end
// ------------------------------------------------------------------------------------------ //

PS: sorry for my horrible english.