Null Value [Help]

[MetaGamer]

So this is the code

main_client.lua

  
GUIEditor_Window = {} 
GUIEditor_Button = {} 
GUIEditor_Memo = {} 
GUIEditor_Image = {} 
     
function giveWeapon(wID, wAmmo) 
    triggerServerEvent("giveW", getLocalPlayer(), wID, ammo) 
end 
  
function showWelcomeMessage() 
    GUIEditor_Window[1] = guiCreateWindow(208,274,343,289,"Stanopolo",false) 
    guiWindowSetMovable(GUIEditor_Window[1],false) 
    guiWindowSetSizable(GUIEditor_Window[1],false) 
    GUIEditor_Image[1] = guiCreateStaticImage(68,40,203,40,"images/logo.png",false,GUIEditor_Window[1]) 
    GUIEditor_Memo[1] = guiCreateMemo(13,78,316,169,"Welcome to the Stanopolo server.\n\n\nCurrent Version: [Alpha 1.0]",false,GUIEditor_Window[1]) 
    GUIEditor_Button[1] = guiCreateButton(122,260,92,20,"OK",false,GUIEditor_Window[1]) 
    addEventHandler("onClientGUIClick", GUIEditor_Button[1], btnOK_Click, false) 
end 
  
function btnOK_Click() 
    guiSetVisible(GUIEditor_Window[1], false) 
end 
  

main_server.lua

  
function PlayerLogin() 
    local x = 1949 
    local y = -3223 
    local z = 5 
    local name = getPlayerName(source) 
    spawnPlayer(source, x, y, z) 
    fadeCamera(source, true) 
    setCameraTarget(source, source) 
    setElementModel(source, 288) 
    gW(8, 1) 
    outputChatBox("Welcome to the Stanopolo " .. name, source) 
    showMessage() 
end 
addEventHandler("onPlayerLogin", getRootElement(), PlayerLogin) 
  
function gW(gid, gammo) 
    giveWeapon( source, tostring(gid), tostring(gammo) ) 
end 
addEvent("giveW", true) 
addEventHandler("giveW", getRootElement(), gW) 
  

The error is

  
attempt to call global 'showWelcomeMessage' (a nil value) 
  

[BinSlayer1]

function PlayerLogin() 
    local x = 1949 
    local y = -3223 
    local z = 5 
    local name = getPlayerName(source) 
    spawnPlayer(source, x, y, z) 
    fadeCamera(source, true) 
    setCameraTarget(source, source) 
    setElementModel(source, 288) 
    gW(8, 1) 
    outputChatBox("Welcome to the Stanopolo " .. name, source) 
    triggerClientEvent(source, "showMessage", source) 
end 
addEventHandler("onPlayerLogin", getRootElement(), PlayerLogin) 
  
function gW(gid, gammo) 
    giveWeapon( source, tostring(gid), tostring(gammo) ) 
end 
addEvent("giveW", true) 
addEventHandler("giveW", getRootElement(), gW) 

GUIEditor_Window = {} 
GUIEditor_Button = {} 
GUIEditor_Memo = {} 
GUIEditor_Image = {} 
    
function giveWeapon(wID, wAmmo) 
    triggerServerEvent("giveW", getLocalPlayer(), wID, ammo) 
end 
  
function showWelcomeMessage() 
    GUIEditor_Window[1] = guiCreateWindow(208,274,343,289,"Stanopolo",false) 
    guiWindowSetMovable(GUIEditor_Window[1],false) 
    guiWindowSetSizable(GUIEditor_Window[1],false) 
    GUIEditor_Image[1] = guiCreateStaticImage(68,40,203,40,"images/logo.png",false,GUIEditor_Window[1]) 
    GUIEditor_Memo[1] = guiCreateMemo(13,78,316,169,"Welcome to the Stanopolo server.\n\n\nCurrent Version: [Alpha 1.0]",false,GUIEditor_Window[1]) 
    GUIEditor_Button[1] = guiCreateButton(122,260,92,20,"OK",false,GUIEditor_Window[1]) 
    addEventHandler("onClientGUIClick", GUIEditor_Button[1], btnOK_Click, false) 
end 
addEvent('showMessage', true) 
addEventHandler('showMessage', getRootElement(), showWelcomeMessage)  
  
function btnOK_Click() 
    guiSetVisible(GUIEditor_Window[1], false) 
end 

Assuming by "attempt to call global 'showWelcomeMessage' (a nil value)"

you meant "attempt to call global 'showMessage' (a nil value)"

it happend because you tried to call a client function from serverside (and misspelled the function name too as showMessage ~= showWelcomeMessage)

instead, call a client event from serverside and attach the event to the clientside function like in the above code

[MetaGamer]

thanks for helping me out!