diff --git a/app/src/processing/app/Base.java b/app/src/processing/app/Base.java
index 2765505dc..a49402e5c 100644
--- a/app/src/processing/app/Base.java
+++ b/app/src/processing/app/Base.java
@@ -788,16 +788,29 @@ public class Base {
       }
 
 //    Editor.State state = new Editor.State(editors);
-      Editor editor = nextMode.createEditor(this, path, state);
+      Editor editor = null;
+      try {
+        editor = nextMode.createEditor(this, path, state);
+
+      } catch (NoSuchMethodError nsme) {
+        Base.showWarning("Mode out of date",
+                         nextMode.getTitle() + " is not compatible with this version of Processing.\n" +
+                         "Try updating the Mode or contact its author for a new version.", nsme);
+      } catch (Throwable t) {
+        showBadnessTrace("Mode Problems",
+                         "A nasty error occurred while trying to use " + nextMode.getTitle() + ".\n" +
+                         "It may not be compatible with this version of Processing.\n" +
+                         "Try updating the Mode or contact its author for a new version.", t, false);
+      }
       if (editor == null) {
-        // if it's not mode[0] already, then don't go into an infinite loop
+        // if the bad mode is the default mode, don't go into an infinite loop
         // trying to recreate a window with the default mode.
         Mode defaultMode = getDefaultMode();
         if (nextMode == defaultMode) {
           Base.showError("Editor Problems",
                          "An error occurred while trying to change modes.\n" +
                          "We'll have to quit for now because it's an\n" +
-                         "unfortunate bit of indigestion.",
+                         "unfortunate bit of indigestion with the default Mode.",
                          null);
         } else {
           editor = defaultMode.createEditor(this, path, state);
@@ -820,6 +833,9 @@ public class Base {
 
       return editor;
 
+//    } catch (NoSuchMethodError nsme) {
+//      Base.showWarning(title, message);
+
     } catch (Throwable t) {
       showBadnessTrace("Terrible News",
                        "A serious error occurred while " +
diff --git a/app/src/processing/app/contrib/ModeContribution.java b/app/src/processing/app/contrib/ModeContribution.java
index e15a72e9f..2203905e2 100644
--- a/app/src/processing/app/contrib/ModeContribution.java
+++ b/app/src/processing/app/contrib/ModeContribution.java
@@ -126,6 +126,12 @@ public class ModeContribution extends LocalContribution {
         if (!existing.containsKey(folder)) {
           try {
             contribModes.add(new ModeContribution(base, folder, null));
+          } catch (NoSuchMethodError nsme) {
+            System.err.println(folder.getName() + " contains an incompatible Mode");
+            System.err.println(nsme.getMessage());
+          } catch (NoClassDefFoundError ncdfe) {
+            System.err.println(folder.getName() + " contains an incompatible Mode");
+            System.err.println(ncdfe.getMessage());
           } catch (IgnorableException ig) {
             Base.log(ig.getMessage());
           } catch (Throwable e) {