triggerServerEvent

[Et-win]

local gSelected = guiGetSelectedTab(SW_S_tabpanel1) 
if (gSelected ~= false) and (gSelected ~= nil) then 
    lol = triggerServerEvent("CWS:onClientRequest:getSettings", getLocalPlayer(), gSelected) 
    outputChatBox(tostring(lol)) 

My question: Why can't I send the selected tab data to Server-side? (Goes from Client to Server and then back to Client for a special handler)

EDIT: When I use toJSON: "Couldn't convert userdata argument to JSON, elements not allowed for this function.". I guess this is my answer, userdata elements are not allowed, but why?

EDIT2: Fixed it on another way, but still want to know why it's blocked