Fixed: 3d floor indicators in 2D modes were not updated after leaving Visual mode.

Source/Core/VisualModes/VisualMode.cs

@@ -235,6 +235,9 @@ namespace CodeImp.DoomBuilder.VisualModes
 			selectedVisualSectors = null;
 			selectedVisualThings = null;
 
+			//mxd. Extra floors may've been edited
+			General.Map.Renderer2D.UpdateExtraFloorFlag();
+
 			// Stop special input mode
 			General.Interface.DisableProcessing();
 			General.Interface.StopExclusiveMouseInput();