Index: /trunk/src/org/openstreetmap/josm/gui/preferences/imagery/AddWMTSLayerPanel.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/preferences/imagery/AddWMTSLayerPanel.java	(revision 15804)
+++ /trunk/src/org/openstreetmap/josm/gui/preferences/imagery/AddWMTSLayerPanel.java	(revision 15805)
@@ -73,5 +73,5 @@
                 layerPanel.add(layerTable, GBC.eol().fill());
                 layerPanel.revalidate();
-            } catch (IOException | WMTSGetCapabilitiesException ex) {
+            } catch (IOException | RuntimeException | WMTSGetCapabilitiesException ex) {
                 Logging.trace(ex);
                 JOptionPane.showMessageDialog(