solved issue on specific version download

src/main/java/org/gcube/data/access/storagehub/handlers/TrashHandler.java

@@ -116,11 +116,12 @@ public class TrashHandler {
 
 				for (Version version: versions) {
 					try {
-						Content content = node2Item.getContent(version);
+						Content content = node2Item.getContentFromVersion(version);
 						if (content!= null && content.getStorageId()!=null)
 							contentSet.add(new ContentPair(content, manager.getStorageBackend()));
+						else log.warn("invalid version {}",version.getName());
 					}catch (Throwable t) {
-						log.warn("error retrieving version {}",version.getName(),t);
+						log.warn("error retrieving version content for {}",version.getName(),t);
 					}
 				}
 			}catch (Exception e) {

src/main/java/org/gcube/data/access/storagehub/handlers/items/Node2ItemConverter.java

@@ -23,6 +23,7 @@ import javax.jcr.PropertyType;
 import javax.jcr.RepositoryException;
 import javax.jcr.Session;
 import javax.jcr.Value;
+import javax.jcr.version.Version;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.jackrabbit.util.Text;
@@ -77,9 +78,9 @@ public class Node2ItemConverter {
 		return item;
 	}
 
-	public Content getContent(Node node) throws RepositoryException, BackendGenericError{
+	public Content getContentFromVersion(Version node) throws RepositoryException, BackendGenericError{
 		Content content = new Content();
-		setGenericFields(node, Content.class, null, content);
+		setGenericFields(node.getFrozenNode(), Content.class, null, content);
 		return content;
 	}
 	

src/main/java/org/gcube/data/access/storagehub/services/ItemsManager.java

@@ -702,11 +702,13 @@ public class ItemsManager extends Impersonable{
 		for (Version version: jcrVersions) {
 			log.debug("retrieved version id {}, name {}", version.getIdentifier(), version.getName());
 			if (version.getName().equals(versionName)) {
-				Content content = node2Item.getContent(version);
-
+				Content content = node2Item.getContentFromVersion(version);
+								
 				FolderManager folderManager = folderPluginHandler.getFolderManager((AbstractFileItem) currentItem);
 				final InputStream streamToWrite = folderManager.getStorageBackend().download(content);
-
+				
+				log.debug("retrieved storage id is {} with storageBackend {} (stream is null? {})",content.getStorageId(), folderManager.getStorageBackend().getClass().getSimpleName(), streamToWrite==null );
+				
 				String oldfilename = FilenameUtils.getBaseName(currentItem.getTitle());
 				String ext = FilenameUtils.getExtension(currentItem.getTitle());