diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/DatasetTypeImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/DatasetTypeImportHelper.java
index 914541fef358653c7fe62d1140837e5ac68a7e68..d78bbecf13157fb261332e700046e164afb36253 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/DatasetTypeImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/DatasetTypeImportHelper.java
@@ -35,7 +35,7 @@ import java.util.Map;
 public class DatasetTypeImportHelper extends BasicImportHelper
 {
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Description("Description", true),
         ValidationScript("Validation script", true),
@@ -84,7 +84,11 @@ public class DatasetTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.DATASET_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.DATASET_TYPE.getType(), code));
+        }
     }
 
     @Override protected void updateVersion(Map<String, Integer> header, List<String> values)
@@ -92,6 +96,12 @@ public class DatasetTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.DATASET_TYPE.getType(), code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.DATASET_TYPE.getType(), code);
     }
 
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/ExperimentTypeImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/ExperimentTypeImportHelper.java
index fd353909a61f4646c935c3f79213c5656096f216..df1eb2cfc55c8169c484d9925a3363be890bc1ae 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/ExperimentTypeImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/ExperimentTypeImportHelper.java
@@ -35,7 +35,7 @@ import java.util.Map;
 public class ExperimentTypeImportHelper extends BasicImportHelper
 {
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Description("Description", true),
         ValidationScript("Validation script", true),
@@ -84,7 +84,11 @@ public class ExperimentTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.EXPERIMENT_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.EXPERIMENT_TYPE.getType(), code));
+        }
     }
 
     @Override protected void updateVersion(Map<String, Integer> header, List<String> values)
@@ -92,6 +96,12 @@ public class ExperimentTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.EXPERIMENT_TYPE.getType(), code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.EXPERIMENT_TYPE.getType(), code);
     }
 
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyAssignmentImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyAssignmentImportHelper.java
index bf22e1a7aa5c401c493a5c3738ce09938581b9dc..90edfeb46e33698816fc33196d0c758e568c49ec 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyAssignmentImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyAssignmentImportHelper.java
@@ -55,7 +55,7 @@ public class PropertyAssignmentImportHelper extends BasicImportHelper
 {
 
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Mandatory("Mandatory", true),
         DefaultValue("Default Value", false),
@@ -119,10 +119,14 @@ public class PropertyAssignmentImportHelper extends BasicImportHelper
 
     @Override protected boolean isNewVersion(Map<String, Integer> header, List<String> values)
     {
-        String newVersion = getValueByColumnName(header, values, PropertyAssignmentImportHelper.Attribute.Version);
+        String version = getValueByColumnName(header, values, PropertyAssignmentImportHelper.Attribute.Version);
         String code = getValueByColumnName(header, values, PropertyAssignmentImportHelper.Attribute.Code);
 
-        return !existingCodes.contains(code) || VersionUtils.isNewVersion(newVersion, VersionUtils.getStoredVersion(beforeVersions, ImportTypes.PROPERTY_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return !existingCodes.contains(code) || VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(beforeVersions, ImportTypes.PROPERTY_TYPE.getType(), code));
+        }
     }
 
     @Override protected boolean isObjectExist(Map<String, Integer> header, List<String> values)
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyTypeImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyTypeImportHelper.java
index dfda7051787365a9b0f16b9d997183f2e7040ac3..f285c33cfe2b6cfeeffca1a3acca2a185c7435b5 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyTypeImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/PropertyTypeImportHelper.java
@@ -52,7 +52,7 @@ public class PropertyTypeImportHelper extends BasicImportHelper
 
     private enum Attribute implements IAttribute
     {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Mandatory("Mandatory", false),
         DefaultValue("Default Value",
@@ -142,11 +142,15 @@ public class PropertyTypeImportHelper extends BasicImportHelper
     @Override
     protected boolean isNewVersion(Map<String, Integer> header, List<String> values)
     {
-        String newVersion = getValueByColumnName(header, values, Attribute.Version);
+        String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(newVersion,
-                VersionUtils.getStoredVersion(versions, ImportTypes.PROPERTY_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version,
+                    VersionUtils.getStoredVersion(versions, ImportTypes.PROPERTY_TYPE.getType(), code));
+        }
     }
 
     @Override
@@ -155,6 +159,12 @@ public class PropertyTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.PROPERTY_TYPE.getType(), code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.PROPERTY_TYPE.getType(), code);
     }
 
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/SampleTypeImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/SampleTypeImportHelper.java
index 7b85b96f7dfcf57258f08db3dfc06019145a99ef..cef78f1424fba54a54efb955f5abeaade93c73d2 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/SampleTypeImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/SampleTypeImportHelper.java
@@ -35,7 +35,7 @@ import java.util.Map;
 public class SampleTypeImportHelper extends BasicImportHelper
 {
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Description("Description", true),
         AutoGenerateCodes("Auto generate codes", true),
@@ -86,7 +86,11 @@ public class SampleTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.SAMPLE_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.SAMPLE_TYPE.getType(), code));
+        }
     }
 
     @Override protected void updateVersion(Map<String, Integer> header, List<String> values)
@@ -94,6 +98,12 @@ public class SampleTypeImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.SAMPLE_TYPE.getType(), code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.SAMPLE_TYPE.getType(), code);
     }
 
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
index 306fcdcfcbd45388ffc191ec9c35174922582e04..5ac9dd9ba448bb3bb0a24e0ecc0a43492b7ca203 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
@@ -34,7 +34,7 @@ import java.util.Map;
 public class VocabularyImportHelper extends BasicImportHelper
 {
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Description("Description", true);
 
@@ -79,7 +79,11 @@ public class VocabularyImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TYPE.getType(), code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TYPE.getType(), code));
+        }
     }
 
     @Override protected void updateVersion(Map<String, Integer> header, List<String> values)
@@ -87,6 +91,12 @@ public class VocabularyImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TYPE.getType(), code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.VOCABULARY_TYPE.getType(), code);
     }
 
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
index 3c1b1bc05cfd56518fe8e60647f00c48f559444b..c84fd86a683f549155cede35de2cdcdae86efc6e 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
@@ -36,7 +36,7 @@ public class VocabularyTermImportHelper extends BasicImportHelper
     private static final String VOCABULARY_CODE_FIELD = "Code";
 
     private enum Attribute implements IAttribute {
-        Version("Version", true),
+        Version("Version", false),
         Code("Code", true),
         Label("Label", true),
         Description("Description", true);
@@ -91,8 +91,12 @@ public class VocabularyTermImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        return VersionUtils.isNewVersion(version,
-                VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TERM.getType() + "-" + vocabularyCode, code));
+        if (version == null) {
+            return true;
+        } else {
+            return VersionUtils.isNewVersion(version,
+                    VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TERM.getType() + "-" + vocabularyCode, code));
+        }
     }
 
     @Override protected void updateVersion(Map<String, Integer> header, List<String> values)
@@ -100,6 +104,12 @@ public class VocabularyTermImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
+        if (version == null) {
+            Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TERM.getType() + "-" + vocabularyCode, code);
+            storedVersion++;
+            version = storedVersion.toString();
+        }
+
         VersionUtils.updateVersion(version, versions, ImportTypes.VOCABULARY_TERM.getType() + "-" + vocabularyCode, code);
     }