diff --git a/Source/Plugins/NodesViewer/NodesViewerMode.cs b/Source/Plugins/NodesViewer/NodesViewerMode.cs
index 304be3cb..25c665a5 100755
--- a/Source/Plugins/NodesViewer/NodesViewerMode.cs
+++ b/Source/Plugins/NodesViewer/NodesViewerMode.cs
@@ -839,6 +839,14 @@ namespace CodeImp.DoomBuilder.Plugins.NodesViewer
 			//mxd
 			if(haveZnodes) 
 			{
+				// For whatever reason ZDBSP reorders the vertices when building the nodes, so if the map was modified in UDB
+				// and then the Nodes Viewer is engaged the vertices in the ZNODES are not the same, resulting in an incorrect
+				// view or even a crash.
+				// See https://github.com/jewalky/UltimateDoomBuilder/issues/659
+				General.Interface.DisplayStatus(StatusType.Warning, "ZNODES are currently not supported.");
+				General.Editing.CancelMode();
+				return;
+
 				General.Interface.DisplayStatus(StatusType.Busy, "Reading map nodes...");
 				if(!LoadZNodes()) 
 				{