Index: /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/downloads/MapillaryTrafficSignDownloaderThread.java
===================================================================
--- /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/downloads/MapillaryTrafficSignDownloaderThread.java	(revision 31473)
+++ /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/downloads/MapillaryTrafficSignDownloaderThread.java	(revision 31474)
@@ -68,5 +68,9 @@
                 if (image instanceof MapillaryImage
                     && ((MapillaryImage) image).getKey().equals(key))
-                  ((MapillaryImage) image).addSign(data.getString("type"));
+                  try {
+                    ((MapillaryImage) image).addSign(data.getString("type"));
+                  } catch (Exception e) {
+                    Main.error("Error when downloading sign.");
+                  }
             }
           }
Index: /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/utils/PluginState.java
===================================================================
--- /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/utils/PluginState.java	(revision 31473)
+++ /applications/editors/josm/plugins/mapillary/src/org/openstreetmap/josm/plugins/mapillary/utils/PluginState.java	(revision 31474)
@@ -2,6 +2,4 @@
 
 import static org.openstreetmap.josm.tools.I18n.tr;
-
-import java.awt.Dimension;
 
 import javax.swing.JDialog;