diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/CommonDialogWindow.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/CommonDialogWindow.java
index 725ff4b9b..a6b05e0a5 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/CommonDialogWindow.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/CommonDialogWindow.java
@@ -96,7 +96,7 @@ public class CommonDialogWindow extends Window implements Serializable {
 
     private final ClickListener close = event -> close();
 
-    private final Map<Component, Object> orginalValues;
+    private final transient Map<Component, Object> orginalValues;
 
     private final List<AbstractField<?>> allComponents;
 
diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/filterlayout/AbstractFilterMultiButtonClick.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/filterlayout/AbstractFilterMultiButtonClick.java
index 8b3ac4cde..f7d3656b1 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/filterlayout/AbstractFilterMultiButtonClick.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/filterlayout/AbstractFilterMultiButtonClick.java
@@ -22,7 +22,8 @@ import com.vaadin.ui.Button.ClickEvent;
  */
 public abstract class AbstractFilterMultiButtonClick extends AbstractFilterButtonClickBehaviour {
 
-    protected final Set<Button> alreadyClickedButtons = new HashSet<>();
+    private static final long serialVersionUID = 1L;
+    protected final transient Set<Button> alreadyClickedButtons = new HashSet<>();
 
     /*
      * (non-Javadoc)
diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java
index 1121ac8a7..b3b74836c 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/table/AbstractTable.java
@@ -95,9 +95,6 @@ public abstract class AbstractTable<E extends NamedEntity, I> extends Table {
         if (values == null) {
             values = Collections.emptySet();
         }
-        if (values.contains(null)) {
-            LOG.warn("Null values in table content. How could this happen?");
-        }
         return values;
     }
 
diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/tagdetails/AbstractTagToken.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/tagdetails/AbstractTagToken.java
index 8d9f5a902..9d36e3de0 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/tagdetails/AbstractTagToken.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/common/tagdetails/AbstractTagToken.java
@@ -43,10 +43,6 @@ import com.vaadin.ui.themes.ValoTheme;
 
 /**
  * Abstract class for target/ds tag token layout.
- *
- *
- *
- *
  */
 public abstract class AbstractTagToken<T extends BaseEntity> implements Serializable {
 
@@ -58,9 +54,9 @@ public abstract class AbstractTagToken<T extends BaseEntity> implements Serializ
 
     protected IndexedContainer container;
 
-    protected final Map<Long, TagData> tagDetails = new HashMap<>();
+    protected final transient Map<Long, TagData> tagDetails = new HashMap<>();
 
-    protected final Map<Long, TagData> tokensAdded = new HashMap<>();
+    protected final transient Map<Long, TagData> tokensAdded = new HashMap<>();
 
     protected CssLayout tokenLayout = new CssLayout();
 
diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetDetails.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetDetails.java
index d51d4fb28..aaeba597d 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetDetails.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/distributions/dstable/DistributionSetDetails.java
@@ -84,7 +84,7 @@ public class DistributionSetDetails extends AbstractNamedVersionedEntityTableDet
 
     private VerticalLayout tagsLayout;
 
-    Map<String, StringBuilder> assignedSWModule = new HashMap<>();
+    private final Map<String, StringBuilder> assignedSWModule = new HashMap<>();
 
     /**
      * softwareLayout Initialize the component.
diff --git a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettable/TargetBeanQuery.java b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettable/TargetBeanQuery.java
index e96a9af8e..aa9f346a1 100644
--- a/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettable/TargetBeanQuery.java
+++ b/hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/management/targettable/TargetBeanQuery.java
@@ -44,7 +44,7 @@ import com.google.common.base.Strings;
 public class TargetBeanQuery extends AbstractBeanQuery<ProxyTarget> {
     private static final long serialVersionUID = -5645680058303167558L;
     private Sort sort = new Sort(SPUIDefinitions.TARGET_TABLE_CREATE_AT_SORT_ORDER, "createdAt");
-    private Collection<TargetUpdateStatus> status = null;
+    private transient Collection<TargetUpdateStatus> status = null;
     private String[] targetTags = null;
     private Long distributionId = null;
     private String searchText = null;