diff --git a/PLUGIN-INF/metadata_SLUBStoragepPlugin.xml b/PLUGIN-INF/metadata_SLUBStoragepPlugin.xml
index 58af2808060a09f270f01f8f64f43a914edcb140..541500cc4ecbaac7e8a572494757eee36b8c387b 100644
--- a/PLUGIN-INF/metadata_SLUBStoragepPlugin.xml
+++ b/PLUGIN-INF/metadata_SLUBStoragepPlugin.xml
@@ -70,7 +70,7 @@
 		</fr:x_form>
 	</pl:initParameters>
 	<pl:description>SLUB Storage Plugin</pl:description>
-	<pl:version>2.810</pl:version>
+	<pl:version>2.813</pl:version>
 	<pl:materialType>DIGITAL</pl:materialType>
 	<pl:module>Repository</pl:module>
 	<pl:generalType>TASK</pl:generalType>
diff --git a/java/org/slub/rosetta/dps/repository/plugin/storage/nfs/SLUBStoragePlugin.java b/java/org/slub/rosetta/dps/repository/plugin/storage/nfs/SLUBStoragePlugin.java
index 8258602f8cec7741a0154a90a0a1b63a9b0440d6..7ca020c6b0611f74046b386fbf9fcee4cc44cdb8 100644
--- a/java/org/slub/rosetta/dps/repository/plugin/storage/nfs/SLUBStoragePlugin.java
+++ b/java/org/slub/rosetta/dps/repository/plugin/storage/nfs/SLUBStoragePlugin.java
@@ -1,6 +1,6 @@
 /*
 
-2014-2016 by Andreas Romeyke (SLUB Dresden)
+2014-2020 by Andreas Romeyke (SLUB Dresden)
 
 The code contributed by SLUB is licensed under apache 2.0 and based partially
 on NFS Storage Plugin, 
@@ -33,10 +33,22 @@ import com.exlibris.digitool.common.dnx.DnxSectionRecord;
 import com.exlibris.digitool.common.storage.Fixity;
 import com.exlibris.digitool.infrastructure.utils.Checksummer;
 
-import java.io.*;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.RandomAccessFile;
 import java.security.NoSuchAlgorithmException;
 import java.text.SimpleDateFormat;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
 
 /**
  * SLUBStoragePlugin
@@ -87,7 +99,7 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
             InputStream is = null;
             try {
                 is = retrieveEntity(storedEntityIdentifier, isRelativePath);
-                Checksummer checksummer = new Checksummer(is, true, true, true);
+                Checksummer checksummer = new Checksummer(is, true, true, true,true);
                 for (Fixity fixity : fixities) {
                     fixity.setResult(false);
                     log.info("SLUBStoragePlugin.checkFixity() getAlgorithm=" + fixity.getAlgorithm());
@@ -114,6 +126,15 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
                     }
                 }
             }
+            catch (IOException e) {
+                log.error("SLUBStoragePlugin.checkFixity(), I/O error, " + e.getMessage());
+            }
+            catch (NoSuchAlgorithmException e) {
+                log.error( "SLUBStoragePlugin.checkFixity(), missed Algorithm, " + e.getMessage());
+            }
+            catch (Exception e) {
+                log.error( "SLUBStoragePlugin.checkFixity(), unknown problem, " + e.getMessage());
+            }
             finally
             {
                 log.info("SLUBStoragePlugin.checkFixity() finally called");
@@ -157,13 +178,19 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
      * @throws Exception
      */
     private boolean checkFixityByPlugin(Fixity fixity, String storedEntityIdentifier, boolean isRelativePath, boolean result) throws Exception {
-        log.info("SLUBStoragePlugin.checkFixity() another fixity");
+        log.info("SLUBStoragePlugin.checkFixityByPlugin() another fixity");
+        String pluginname;
         try {
-            log.info("SLUBStoragePlugin.checkFixity() pluginname=" + fixity.getPluginName());
+            pluginname = fixity.getPluginName();
+            log.info("SLUBStoragePlugin.checkFixity() pluginname=" + pluginname);
         }
         catch (Exception e) {
-            log.warn("SLUBStoragePlugin failed to get pluginname ", e.getMessage());
+            pluginname = "";
         }
+        if (pluginname.isEmpty()) {
+            log.error("SLUBStoragePlugin failed to get pluginname, because it is empty. Possibly, there is no valid fixity typeused or a CustomFixityPlugin missed");
+        }
+
         String oldValue = "";
         try {
             oldValue = fixity.getValue();
@@ -222,7 +249,7 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
     public byte[] retrieveEntityByRange(String storedEntityIdentifier, long start, long end)
             throws Exception
     {
-        log.info("SLUBStoragePlugin.retrieveEntitybyRange() with '" + storedEntityIdentifier + "' start=" + start + "end=" + end);
+        log.info("SLUBStoragePlugin.retrieveEntitybyRange() with '" + storedEntityIdentifier + "' start=" + start + " end=" + end);
         byte[] bytes = new byte[(int)(end - start + 1L)];
         RandomAccessFile file = null;
         try
@@ -230,7 +257,13 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
             file = new RandomAccessFile(this.parameters.get("DIR_ROOT") + storedEntityIdentifier, "r");
             file.seek(start);
             file.readFully(bytes, 0, (int)(end - start + 1L));
-            return bytes;
+
+        }
+        catch (FileNotFoundException e) {
+            log.error("SLUBStoragePlugin.retrieveEntitybyRange(), file not found, " + e.getMessage());
+        }
+        catch (Exception e) {
+            log.error("SLUBStoragePlugin.retrieveEntityByRange(), I/O error, " + e.getMessage());
         }
         finally
         {
@@ -241,11 +274,13 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
                 }
                 catch (Exception e)
                 {
-                    log.warn("Failed closing file", e.getMessage());
+                    log.error("Failed closing file", e.getMessage());
                 }
             }
         }
+        return bytes;
     }
+
     public String storeEntity(InputStream is, StoredEntityMetaData storedEntityMetadata)
             throws Exception
     {
@@ -305,6 +340,7 @@ public class SLUBStoragePlugin extends AbstractStorageHandler {
         log.debug("SLUBStoragePlugin.storeEntity() storedEntityIdentifier (2)='" + storedEntityIdentifier + "'");
         return storedEntityIdentifier;
     }
+
     protected void copyStream(StoredEntityMetaData storedEntityMetadata, String destPath)
             throws IOException
     {