Index: src/org/openstreetmap/josm/actions/SaveActionBase.java
===================================================================
--- src/org/openstreetmap/josm/actions/SaveActionBase.java	(revision 14726)
+++ src/org/openstreetmap/josm/actions/SaveActionBase.java	(working copy)
@@ -121,6 +121,9 @@
             }
             MainApplication.getMainFrame().repaint();
         } catch (IOException e) {
+            GuiHelper.runInEDT(() ->
+            JOptionPane.showMessageDialog(MainApplication.getMainFrame(), tr("Export failed: {0}", e.getMessage()), tr("Warning"),
+                    JOptionPane.WARNING_MESSAGE));
             Logging.error(e);
             return false;
         }