Index: trunk/src/org/openstreetmap/josm/gui/layer/MainLayerManager.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/MainLayerManager.java	(revision 13216)
+++ trunk/src/org/openstreetmap/josm/gui/layer/MainLayerManager.java	(revision 13219)
@@ -17,4 +17,5 @@
 import org.openstreetmap.josm.gui.io.AsynchronousUploadPrimitivesTask;
 import org.openstreetmap.josm.gui.util.GuiHelper;
+import org.openstreetmap.josm.tools.Logging;
 
 /**
@@ -426,7 +427,10 @@
             activeLayerChangeListeners.clear();
             layerAvailabilityListeners.clear();
-        } else if (!GraphicsEnvironment.isHeadless()) {
-            GuiHelper.runInEDT(() -> JOptionPane.showMessageDialog(MainApplication.parent,
-                    tr("A background upload is already in progress. Cannot reset state until the upload is finished.")));
+        } else {
+            String msg = tr("A background upload is already in progress. Cannot reset state until the upload is finished.");
+            Logging.warn(msg);
+            if (!GraphicsEnvironment.isHeadless()) {
+                GuiHelper.runInEDT(() -> JOptionPane.showMessageDialog(MainApplication.parent, msg));
+            }
         }
     }