Index: /applications/editors/josm/plugins/imagerycache/src/org/openstreetmap/josm/plugins/imagerycache/DBTile.java
===================================================================
--- /applications/editors/josm/plugins/imagerycache/src/org/openstreetmap/josm/plugins/imagerycache/DBTile.java	(revision 30134)
+++ /applications/editors/josm/plugins/imagerycache/src/org/openstreetmap/josm/plugins/imagerycache/DBTile.java	(revision 30135)
@@ -15,5 +15,9 @@
     public DBTile(DBTile dbTile) {
         data = dbTile.data.clone();
-        metaData = new HashMap<String, String>(dbTile.metaData);
+        if (dbTile.metaData != null) {
+            metaData = new HashMap<String, String>(dbTile.metaData);
+        } else {
+            metaData = new HashMap<String, String>();
+        }
         lastModified = dbTile.lastModified;
     }