client: 
function SubmitAbbrechenBtn( button ) 
    guiSetVisible(GUIEditor.window[1],false) 
    showCursor(false) 
    triggerServerEvent ( "cancel_gui_server", lp ) 
end 
  
GUIEditor.window[1] = {} 
  
function createGui () 
local screenwidth, screenheight = guiGetScreenSize () 
  
    GUIEditor.window[1] = guiCreateWindow(screenwidth/2-411,screenheight/2-285/2,411, 285, "miau", false) 
    guiWindowSetSizable(GUIEditor.window[1], false) 
  
    GUIEditor.label[1] = guiCreateLabel(-10, 32, 434, 15, "miau", false, GUIEditor.window[1]) 
    guiLabelSetHorizontalAlign(GUIEditor.label[1], "center", false) 
  
    GUIEditor.label[2] = guiCreateLabel(-21, 11, 15, 15, "", false, GUIEditor.label[1]) 
  
    GUIEditor.label[3] = guiCreateLabel(30, 69, 357, 15, "miau", false, GUIEditor.window[1]) 
    GUIEditor.label[4] = guiCreateLabel(28, 86, 360, 18, "miau", false, GUIEditor.window[1]) 
  
    GUIEditor.label[5] = guiCreateLabel(0, 18, 354, 16, "", false, GUIEditor.label[4]) 
  
    GUIEditor.label[6] = guiCreateLabel(26, 104, 363, 18, "miau", false, GUIEditor.window[1]) 
    guiLabelSetHorizontalAlign(GUIEditor.label[6], "center", false) 
    GUIEditor.label[7] = guiCreateLabel(25, 123, 364, 19, "miau.", false, GUIEditor.window[1]) 
    guiLabelSetHorizontalAlign(GUIEditor.label[7], "center", false) 
    GUIEditor.label[8] = guiCreateLabel(109, 50, 201, 15, "miau.", false, GUIEditor.window[1]) 
    guiLabelSetHorizontalAlign(GUIEditor.label[8], "center", false) 
    GUIEditor.label[9] = guiCreateLabel(36, 161, 336, 20, "miau", false, GUIEditor.window[1]) 
    guiLabelSetColor(GUIEditor.label[9], 222, 101, 20) 
    guiLabelSetHorizontalAlign(GUIEditor.label[9], "center", false) 
    GUIEditor.button[1] = guiCreateButton(99, 191, 210, 53, "miau", false, GUIEditor.window[1]) 
    GUIEditor.button[2]Schliessen = guiCreateButton(328, 260, 73, 15, "Schliessen", false, GUIEditor.window[1])    
addEventHandler("onClientGUIClick", GUIEditor.button[2]Schliessen, SubmitAbbrechenBtn, true)     
end 
addEvent ( "_createGui", true ) 
addEventHandler ( "_createGui", getRootElement (), createGui ) 
 
server:  
markerzurpruefung = createMarker ( 1173.176, 1348.323, 10.922, "cylinder", 1, 255, 0, 0, 170 ) 
  
function pruefung_marker ( marker ) 
    local player = source 
    if getPedOccupiedVehicle ( player ) == false then 
        if marker == markerzurpruefung then 
            triggerClientEvent ( player, "_createGui" , player ) 
            showCursor ( player, true) 
        end 
    end  
end 
addEventHandler ( "onPlayerMarkerHit", getRootElement (), pruefung_marker) 
 
Error:  
 
Help me