Index: /applications/editors/josm/plugins/photoadjust/src/org/openstreetmap/josm/plugins/photoadjust/PhotoPropertyEditor.java
===================================================================
--- /applications/editors/josm/plugins/photoadjust/src/org/openstreetmap/josm/plugins/photoadjust/PhotoPropertyEditor.java	(revision 35766)
+++ /applications/editors/josm/plugins/photoadjust/src/org/openstreetmap/josm/plugins/photoadjust/PhotoPropertyEditor.java	(revision 35767)
@@ -67,4 +67,6 @@
      */
     private static class PropertyEditorAction extends JosmAction implements LayerChangeListener, ImageDataUpdateListener {
+        boolean imgDataUpdLstReg = false;
+
         public PropertyEditorAction() {
             super(tr("Edit photo GPS data"),  // String name
@@ -135,4 +137,5 @@
             if (layer instanceof GeoImageLayer) {
                 ((GeoImageLayer) layer).getImageData().addImageDataUpdateListener(this);
+                imgDataUpdLstReg = true;
             }
         }
@@ -143,5 +146,11 @@
 
             if (layer instanceof GeoImageLayer) {
-                ((GeoImageLayer) layer).getImageData().removeImageDataUpdateListener(this);
+                // In some combinations the listener might not be registered,
+                // e.g. if the plugin was added while the geo image layer
+                // existed and then the layer is removed.
+                if (imgDataUpdLstReg) {
+                    ((GeoImageLayer) layer).getImageData().removeImageDataUpdateListener(this);
+                    imgDataUpdLstReg = false;
+                }
             }
             this.updateEnabledState();