diff --git a/worldedit_gui/init.lua b/worldedit_gui/init.lua
index d44d8bb..137a057 100644
--- a/worldedit_gui/init.lua
+++ b/worldedit_gui/init.lua
@@ -171,82 +171,14 @@ elseif rawget(_G, "sfinv") then --sfinv installed (part of minetest_game since 0
 			player:set_inventory_formspec(get_formspec(name, page))
 		end
 	end
-else --fallback button
-	-- FIXME: this is a huge clusterfuck and the back button is broken
-	local player_formspecs = {}
-
-	local update_main_formspec = function(name)
-		local formspec = player_formspecs[name]
-		if not formspec then
-			return
-		end
-		local player = minetest.get_player_by_name(name)
-		if not player then --this is in case the player signs off while the media is loading
-			return
-		end
-		if (minetest.check_player_privs(name, {creative=true}) or
-				minetest.setting_getbool("creative_mode")) and
-				creative then --creative is active, add button to modified formspec
-			local creative_formspec = player:get_inventory_formspec()
-			local tab_id = tonumber(creative_formspec:match("tabheader%[.-;(%d+)%;"))
-
-			if tab_id == 1 then
-				formspec = creative_formspec ..
-					"image_button[0,1;1,1;inventory_plus_worldedit_gui.png;worldedit_gui;]"
-			elseif not tab_id then
-				formspec = creative_formspec ..
-					"image_button[6,0;1,1;inventory_plus_worldedit_gui.png;worldedit_gui;]"
-			else
-				return
-			end
-		else
-			formspec = formspec .. "image_button[0,0;1,1;inventory_plus_worldedit_gui.png;worldedit_gui;]"
-		end
-		player:set_inventory_formspec(formspec)
-	end
-
-	minetest.register_on_joinplayer(function(player)
-		local name = player:get_player_name()
-		minetest.after(1, function()
-			if minetest.get_player_by_name(name) then --ensure the player is still signed in
-				player_formspecs[name] = player:get_inventory_formspec()
-				minetest.after(0.01, function()
-					update_main_formspec(name)
-				end)
-			end
-		end)
-	end)
-
-	minetest.register_on_leaveplayer(function(player)
-		player_formspecs[player:get_player_name()] = nil
-	end)
-
-	local gui_player_formspecs = {}
-	minetest.register_on_player_receive_fields(function(player, formname, fields)
-		local name = player:get_player_name()
-		if fields.worldedit_gui then --main page
-			gui_player_formspecs[name] = player:get_inventory_formspec()
-			worldedit.show_page(name, "worldedit_gui")
-			return true
-		elseif fields.worldedit_gui_exit then --return to original page
-			if gui_player_formspecs[name] then
-				player:set_inventory_formspec(gui_player_formspecs[name])
-			end
-			return true
-		else --deal with creative_inventory setting the formspec on every single message
-			minetest.after(0.01,function()
-				update_main_formspec(name)
-			end)
-			return false --continue processing in creative inventory
-		end
-	end)
-
-	worldedit.show_page = function(name, page)
-		local player = minetest.get_player_by_name(name)
-		if player then
-			player:set_inventory_formspec(get_formspec(name, page))
-		end
-	end
+else
+	error(
+		"worldedit_gui requires a supported \"gui management\" mod to be installed\n"..
+		"To use the GUI you need to either\n"..
+		"* Use minetest_game (at least 0.4.15) or a subgame with compatible sfinv\n"..
+		"* Install Unified Inventory or Inventory++\n"..
+		"If you do not want to use worldedit_gui, disable it by editing world.mt or from the Main Menu"
+	)
 end
 
 worldedit.register_gui_function("worldedit_gui", {