Index: /applications/editors/josm/plugins/MicrosoftStreetside/src/org/openstreetmap/josm/plugins/streetside/cubemap/CubemapBuilder.java
===================================================================
--- /applications/editors/josm/plugins/MicrosoftStreetside/src/org/openstreetmap/josm/plugins/streetside/cubemap/CubemapBuilder.java	(revision 34417)
+++ /applications/editors/josm/plugins/MicrosoftStreetside/src/org/openstreetmap/josm/plugins/streetside/cubemap/CubemapBuilder.java	(revision 34418)
@@ -9,4 +9,5 @@
 import java.util.Map;
 import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
@@ -34,5 +35,5 @@
 	protected boolean cancelled;
 	private long startTime;
-  private Map<String, BufferedImage> tileImages = new HashMap<>();
+  private Map<String, BufferedImage> tileImages = new ConcurrentHashMap();//new HashMap<>();
 
   /**