Index: src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java =================================================================== --- src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java (revision 17348) +++ src/org/openstreetmap/josm/gui/preferences/PreferenceTabbedPane.java (working copy) @@ -489,6 +489,10 @@ for (PreferenceSettingFactory factory : factories) { if (factory != null) { PreferenceSetting setting = factory.createPreferenceSetting(); + if (setting instanceof TabPreferenceSetting && ((TabPreferenceSetting) setting).getIconName() == null) { + Logging.error("Invalid setting (Icon missing): " + setting.getClass().getName()); + setting = null; + } if (setting != null) { settings.add(setting); } @@ -523,7 +527,7 @@ insertTab(title, icon, component, tps.getTooltip(), position); } - private String htmlTabTitle(String title, int maxWidth) { + private static String htmlTabTitle(String title, int maxWidth) { // Width is set to force left alignment, see https://stackoverflow.com/a/33781096/2257172 return "
" + title + "
"; }