Index: trunk/src/org/openstreetmap/josm/gui/MainApplication.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 12134)
+++ trunk/src/org/openstreetmap/josm/gui/MainApplication.java	(revision 12135)
@@ -452,5 +452,5 @@
         monitor.indeterminateSubTask(tr("Loading plugins"));
         PluginHandler.loadLatePlugins(splash, pluginsToLoad, monitor.createSubTaskMonitor(1, false));
-        toolbar.refreshToolbarControl();
+        GuiHelper.runInEDTAndWait(() -> toolbar.refreshToolbarControl());
     }
 
Index: trunk/src/org/openstreetmap/josm/gui/preferences/ToolbarPreferences.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/ToolbarPreferences.java	(revision 12134)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/ToolbarPreferences.java	(revision 12135)
@@ -69,4 +69,5 @@
 import org.openstreetmap.josm.data.imagery.ImageryLayerInfo;
 import org.openstreetmap.josm.gui.tagging.presets.TaggingPreset;
+import org.openstreetmap.josm.gui.util.GuiHelper;
 import org.openstreetmap.josm.tools.GBC;
 import org.openstreetmap.josm.tools.ImageProvider;
@@ -995,6 +996,8 @@
      */
     public ToolbarPreferences() {
-        control.setFloatable(false);
-        control.setComponentPopupMenu(popupMenu);
+        GuiHelper.runInEDTAndWait(() -> {
+            control.setFloatable(false);
+            control.setComponentPopupMenu(popupMenu);
+        });
         Main.pref.addPreferenceChangeListener(e -> {
             if ("toolbar.visible".equals(e.getKey())) {
@@ -1110,10 +1113,10 @@
         if (toolbar == null) {
             Main.info(tr("Registered toolbar action without name: {0}",
-            action.getClass().getName()));
+                action.getClass().getName()));
         } else {
             Action r = regactions.get(toolbar);
             if (r != null) {
                 Main.info(tr("Registered toolbar action {0} overwritten: {1} gets {2}",
-                toolbar, r.getClass().getName(), action.getClass().getName()));
+                    toolbar, r.getClass().getName(), action.getClass().getName()));
             }
         }