diff --git a/docs/pom.xml b/docs/pom.xml
index 8c63eaf3..88ed4288 100644
--- a/docs/pom.xml
+++ b/docs/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data</groupId>
     <artifactId>camunda-bpm-data-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-docs</artifactId>
diff --git a/example/coverage-report-aggregator/pom.xml b/example/coverage-report-aggregator/pom.xml
index 7bfef642..008a6baa 100644
--- a/example/coverage-report-aggregator/pom.xml
+++ b/example/coverage-report-aggregator/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data.example</groupId>
     <artifactId>camunda-bpm-data-example-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-coverage-report</artifactId>
diff --git a/example/example-java/pom.xml b/example/example-java/pom.xml
index 40462e51..fe91facd 100644
--- a/example/example-java/pom.xml
+++ b/example/example-java/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data.example</groupId>
     <artifactId>camunda-bpm-data-example-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-example-java</artifactId>
diff --git a/example/example-kotlin/pom.xml b/example/example-kotlin/pom.xml
index 4d5e0aa1..8067539b 100644
--- a/example/example-kotlin/pom.xml
+++ b/example/example-kotlin/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data.example</groupId>
     <artifactId>camunda-bpm-data-example-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-example-kotlin</artifactId>
diff --git a/example/itest/pom.xml b/example/itest/pom.xml
index 8f0602a8..1d5c646a 100644
--- a/example/itest/pom.xml
+++ b/example/itest/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data.example</groupId>
     <artifactId>camunda-bpm-data-example-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-integration-test</artifactId>
diff --git a/example/pom.xml b/example/pom.xml
index 269dc38c..54459a57 100644
--- a/example/pom.xml
+++ b/example/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data</groupId>
     <artifactId>camunda-bpm-data-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <groupId>io.holunda.data.example</groupId>
@@ -59,7 +59,7 @@
       <dependency>
         <groupId>io.holunda.testing</groupId>
         <artifactId>camunda-bpm-jgiven</artifactId>
-        <version>0.0.5</version>
+        <version>0.0.7</version>
         <scope>test</scope>
       </dependency>
       <dependency>
diff --git a/example/spin-type-detector/pom.xml b/example/spin-type-detector/pom.xml
index 1f05241b..cde809ba 100644
--- a/example/spin-type-detector/pom.xml
+++ b/example/spin-type-detector/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data.example</groupId>
     <artifactId>camunda-bpm-data-example-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
   </parent>
 
   <artifactId>camunda-bpm-data-spin-type-detector</artifactId>
diff --git a/extension/core/pom.xml b/extension/core/pom.xml
index ef3980b2..018a029e 100644
--- a/extension/core/pom.xml
+++ b/extension/core/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data</groupId>
     <artifactId>camunda-bpm-data-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
diff --git a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/list/ListReadAdapterLockedExternalTask.java b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/list/ListReadAdapterLockedExternalTask.java
index d47412eb..efee4f18 100644
--- a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/list/ListReadAdapterLockedExternalTask.java
+++ b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/list/ListReadAdapterLockedExternalTask.java
@@ -3,6 +3,7 @@
 import io.holunda.camunda.bpm.data.adapter.ReadAdapter;
 import io.holunda.camunda.bpm.data.adapter.WrongVariableTypeException;
 import org.camunda.bpm.engine.externaltask.LockedExternalTask;
+import org.camunda.bpm.engine.variable.Variables;
 
 import java.util.Collections;
 import java.util.List;
@@ -28,7 +29,7 @@ public ListReadAdapterLockedExternalTask(LockedExternalTask lockedExternalTask,
 
   @Override
   public List<T> get() {
-    return null;
+    return getOptional().get();
   }
 
   @Override
@@ -90,6 +91,8 @@ private List<T> getOrNull(T value) {
   }
 
   private T getValue() {
-    return (T) Optional.ofNullable(lockedExternalTask.getVariables()).map(it -> it.get(variableName)).get();
+    return (T) Optional.ofNullable(lockedExternalTask.getVariables())
+      .orElse(Variables.createVariables())
+      .get(variableName);
   }
 }
diff --git a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/map/MapReadAdapterLockedExternalTask.java b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/map/MapReadAdapterLockedExternalTask.java
index f1011ae2..8bca8fd3 100644
--- a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/map/MapReadAdapterLockedExternalTask.java
+++ b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/map/MapReadAdapterLockedExternalTask.java
@@ -3,6 +3,7 @@
 import io.holunda.camunda.bpm.data.adapter.ReadAdapter;
 import io.holunda.camunda.bpm.data.adapter.WrongVariableTypeException;
 import org.camunda.bpm.engine.externaltask.LockedExternalTask;
+import org.camunda.bpm.engine.variable.Variables;
 
 import java.util.Collections;
 import java.util.Map;
@@ -31,47 +32,47 @@ public MapReadAdapterLockedExternalTask(LockedExternalTask lockedExternalTask, S
 
   @Override
   public Map<K, V> get() {
-    return null;
+    return getOptional().get();
   }
 
   @Override
   @SuppressWarnings("java:S3655")
-  public Optional<Map<K,V>> getOptional() {
+  public Optional<Map<K, V>> getOptional() {
     return Optional.ofNullable(getOrNull(getValue()));
   }
 
   @Override
-  public Map<K,V> getLocal() {
+  public Map<K, V> getLocal() {
     throw new UnsupportedOperationException("Can't get a local variable on an external task");
   }
 
   @Override
-  public Optional<Map<K,V>> getLocalOptional() {
+  public Optional<Map<K, V>> getLocalOptional() {
     throw new UnsupportedOperationException("Can't get a local variable on an external task");
   }
 
   @Override
-  public Map<K,V> getOrDefault(Map<K,V> defaultValue) {
+  public Map<K, V> getOrDefault(Map<K, V> defaultValue) {
     return getOptional().orElse(defaultValue);
   }
 
   @Override
-  public Map<K,V> getLocalOrDefault(Map<K,V> defaultValue) {
+  public Map<K, V> getLocalOrDefault(Map<K, V> defaultValue) {
     throw new UnsupportedOperationException("Can't get a local variable on an external task");
   }
 
   @Override
-  public Map<K,V> getOrNull() {
+  public Map<K, V> getOrNull() {
     return getOrNull(getValue());
   }
 
   @Override
-  public Map<K,V> getLocalOrNull() {
+  public Map<K, V> getLocalOrNull() {
     throw new UnsupportedOperationException("Can't get a local variable on an external task");
   }
 
   @SuppressWarnings("Duplicates")
-  private Map<K,V> getOrNull(Object value) {
+  private Map<K, V> getOrNull(Object value) {
     if (value == null) {
       return null;
     }
@@ -96,6 +97,8 @@ private Map<K,V> getOrNull(Object value) {
   }
 
   private Object getValue() {
-    return Optional.ofNullable(lockedExternalTask.getVariables()).map(it -> it.get(variableName)).get();
+    return Optional.ofNullable(lockedExternalTask.getVariables())
+      .orElse(Variables.createVariables())
+      .get(variableName);
   }
 }
diff --git a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/set/SetReadAdapterLockedExternalTask.java b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/set/SetReadAdapterLockedExternalTask.java
index 21b25a63..574b9ae8 100644
--- a/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/set/SetReadAdapterLockedExternalTask.java
+++ b/extension/core/src/main/java/io/holunda/camunda/bpm/data/adapter/set/SetReadAdapterLockedExternalTask.java
@@ -3,9 +3,9 @@
 import io.holunda.camunda.bpm.data.adapter.ReadAdapter;
 import io.holunda.camunda.bpm.data.adapter.WrongVariableTypeException;
 import org.camunda.bpm.engine.externaltask.LockedExternalTask;
+import org.camunda.bpm.engine.variable.Variables;
 
 import java.util.Collections;
-import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 
@@ -29,7 +29,7 @@ public SetReadAdapterLockedExternalTask(LockedExternalTask lockedExternalTask, S
 
   @Override
   public Set<T> get() {
-    return null;
+    return getOptional().get();
   }
 
   @Override
@@ -74,8 +74,8 @@ private Set<T> getOrNull(T value) {
       return null;
     }
 
-    if (List.class.isAssignableFrom(value.getClass())) {
-      List<?> valueAsSet = (List<?>) value;
+    if (Set.class.isAssignableFrom(value.getClass())) {
+      Set<?> valueAsSet = (Set<?>) value;
       if (valueAsSet.isEmpty()) {
         return Collections.emptySet();
       } else {
@@ -91,6 +91,8 @@ private Set<T> getOrNull(T value) {
   }
 
   private T getValue() {
-    return (T) Optional.ofNullable(lockedExternalTask.getVariables()).map(it -> it.get(variableName)).get();
+    return (T) Optional.ofNullable(lockedExternalTask.getVariables())
+      .orElse(Variables.createVariables())
+      .get(variableName);
   }
 }
diff --git a/extension/core/src/test/java/io/holunda/camunda/bpm/data/reader/LockedExternalTaskReaderTest.java b/extension/core/src/test/java/io/holunda/camunda/bpm/data/reader/LockedExternalTaskReaderTest.java
index 94b512bb..e9d1b039 100644
--- a/extension/core/src/test/java/io/holunda/camunda/bpm/data/reader/LockedExternalTaskReaderTest.java
+++ b/extension/core/src/test/java/io/holunda/camunda/bpm/data/reader/LockedExternalTaskReaderTest.java
@@ -7,17 +7,32 @@
 import org.junit.Before;
 import org.junit.Test;
 
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static io.holunda.camunda.bpm.data.CamundaBpmData.listVariable;
+import static io.holunda.camunda.bpm.data.CamundaBpmData.mapVariable;
+import static io.holunda.camunda.bpm.data.CamundaBpmData.setVariable;
 import static io.holunda.camunda.bpm.data.CamundaBpmData.stringVariable;
+import static java.util.Arrays.asList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.camunda.bpm.engine.impl.util.CollectionUtil.asHashSet;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 public class LockedExternalTaskReaderTest {
 
   private static final VariableFactory<String> STRING = stringVariable("myString");
+  private static final VariableFactory<List<String>> LIST = listVariable("myList", String.class);
+  private static final VariableFactory<Set<String>> SET = setVariable("mySet", String.class);
+  private static final VariableFactory<Map<String, String>> MAP = mapVariable("myMap", String.class, String.class);
 
-  private final String value = "value";
+  private final String stringValue = "value";
+  private final List<String> listValue = asList("foo", "bar");
+  private final Set<String> setValue = asHashSet("foo", "bar");
+  private final Map<String, String> mapValue = Map.of("a", "b", "c", "d");
 
   LockedExternalTask externalTask = mock(LockedExternalTask.class);
   private VariableReader reader = CamundaBpmData.reader(externalTask);
@@ -25,17 +40,29 @@ public class LockedExternalTaskReaderTest {
 
   @Before
   public void setUp() {
-    when(externalTask.getVariables()).thenReturn(Variables.putValue(STRING.getName(), value));
+    when(externalTask.getVariables()).thenReturn(
+      Variables
+        .putValue(STRING.getName(), stringValue)
+        .putValue(LIST.getName(), listValue)
+        .putValue(SET.getName(), setValue)
+        .putValue(MAP.getName(), mapValue)
+    );
   }
 
   @Test
   public void shouldDelegateGet() {
-    assertThat(reader.get(STRING)).isEqualTo(value);
+    assertThat(reader.get(STRING)).isEqualTo(stringValue);
+    assertThat(reader.get(LIST)).isEqualTo(listValue);
+    assertThat(reader.get(SET)).isEqualTo(setValue);
+    assertThat(reader.get(MAP)).isEqualTo(mapValue);
   }
 
   @Test
   public void shouldDelegateGetOptional() {
-    assertThat(reader.getOptional(STRING)).hasValue(value);
+    assertThat(reader.getOptional(STRING)).hasValue(stringValue);
+    assertThat(reader.getOptional(LIST)).hasValue(listValue);
+    assertThat(reader.getOptional(SET)).hasValue(setValue);
+    assertThat(reader.getOptional(MAP)).hasValue(mapValue);
     assertThat(reader.getOptional(stringVariable("xxx"))).isEmpty();
   }
 
@@ -55,7 +82,10 @@ public void shouldDelegateGetLocal() {
 
   @Test
   public void shouldDelegateGetOrNull() {
-    assertThat(reader.getOrNull(STRING)).isEqualTo(value);
+    assertThat(reader.getOrNull(STRING)).isEqualTo(stringValue);
+    assertThat(reader.getOrNull(LIST)).isEqualTo(listValue);
+    assertThat(reader.getOrNull(SET)).isEqualTo(setValue);
+    assertThat(reader.getOrNull(MAP)).isEqualTo(mapValue);
     assertThat(reader.getOrNull(stringVariable("xxx"))).isNull();
   }
 
@@ -68,14 +98,20 @@ public void shouldDelegateGetLocalOrNull() {
 
   @Test
   public void shouldDelegateGetOrDefault() {
-    assertThat(reader.getOrDefault(STRING, "default")).isEqualTo(value);
-    assertThat(reader.getOrDefault(stringVariable("xxx"), "default")).isEqualTo("default");
+    assertThat(reader.getOrDefault(STRING, "default")).isEqualTo(stringValue);
+    assertThat(reader.getOrDefault(LIST, asList("a", "b"))).isEqualTo(listValue);
+    assertThat(reader.getOrDefault(SET, asHashSet("a", "b"))).isEqualTo(setValue);
+    assertThat(reader.getOrDefault(MAP, Map.of("a", "b", "c", "d"))).isEqualTo(mapValue);
 
+    assertThat(reader.getOrDefault(stringVariable("xxx"), "default")).isEqualTo("default");
+    assertThat(reader.getOrDefault(listVariable("xxx", String.class), asList("a", "b"))).isEqualTo(asList("a", "b"));
+    assertThat(reader.getOrDefault(setVariable("xxx", String.class), asHashSet("a", "b"))).isEqualTo(asHashSet("a", "b"));
+    assertThat(reader.getOrDefault(mapVariable("xxx", String.class, String.class), Map.of("a", "b", "c", "d"))).isEqualTo(Map.of("a", "b", "c", "d"));
   }
 
   @Test
   public void shouldDelegateGetLocalOrDefault() {
-    assertThatThrownBy(() -> reader.getLocalOrDefault(STRING, value))
+    assertThatThrownBy(() -> reader.getLocalOrDefault(STRING, stringValue))
       .isInstanceOf(UnsupportedOperationException.class)
       .hasMessage("Can't get a local variable on an external task");
   }
diff --git a/extension/test/pom.xml b/extension/test/pom.xml
index 6a561126..6525f180 100644
--- a/extension/test/pom.xml
+++ b/extension/test/pom.xml
@@ -6,7 +6,7 @@
   <parent>
     <groupId>io.holunda.data</groupId>
     <artifactId>camunda-bpm-data-parent</artifactId>
-    <version>1.2.2</version>
+    <version>1.2.3</version>
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
diff --git a/pom.xml b/pom.xml
index 5a18502f..f8d31737 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>io.holunda.data</groupId>
   <artifactId>camunda-bpm-data-parent</artifactId>
-  <version>1.2.2</version>
+  <version>1.2.3</version>
   <name>${project.artifactId}</name>
   <description>Camunda BPM Data</description>
   <url>https://github.com/holunda-io/camunda-bpm-data/</url>
@@ -21,19 +21,19 @@
     <camunda.version.ce>7.15.0</camunda.version.ce>
     <camunda.version.ee>7.15.0-ee</camunda.version.ee>
 
-    <spring-boot.version>2.4.4</spring-boot.version>
-    <groovy.version>2.4.5</groovy.version>
+    <spring-boot.version>2.4.5</spring-boot.version>
+    <groovy.version>2.4.21</groovy.version>
     <spin.version>1.10.1</spin.version>
     <camunda-assert.version>10.0.0</camunda-assert.version>
 
     <jgiven.version>0.18.2</jgiven.version>
-    <kotlin.version>1.4.21</kotlin.version>
+    <kotlin.version>1.4.32</kotlin.version>
     <kotlin.compiler.incremental>true</kotlin.compiler.incremental>
 
-    <kotlin-logging.version>2.0.2</kotlin-logging.version>
+    <kotlin-logging.version>2.0.6</kotlin-logging.version>
     <mockito-kotlin.version>2.2.0</mockito-kotlin.version>
-    <camunda-bpm-mockito.version>4.12.0</camunda-bpm-mockito.version>
-    <mockito.version>2.23.4</mockito.version>
+    <camunda-bpm-mockito.version>5.15.0</camunda-bpm-mockito.version>
+    <mockito.version>3.9.0</mockito.version>
 
     <pattern.class.itest>**/*ITest.*</pattern.class.itest>
     <pattern.package.itest>**/itest/**/*.*</pattern.package.itest>
@@ -125,7 +125,7 @@
     <dependency>
       <groupId>org.jetbrains</groupId>
       <artifactId>annotations</artifactId>
-      <version>18.0.0</version>
+      <version>20.1.0</version>
     </dependency>
 
     <!-- Engine -->
@@ -309,7 +309,7 @@
           <!-- resources -->
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-resources-plugin</artifactId>
-          <version>3.1.0</version>
+          <version>3.2.0</version>
           <configuration>
             <encoding>${project.build.sourceEncoding}</encoding>
           </configuration>
@@ -347,7 +347,7 @@
         <plugin>
           <groupId>org.jetbrains.dokka</groupId>
           <artifactId>dokka-maven-plugin</artifactId>
-          <version>1.4.10.2</version>
+          <version>1.4.32</version>
           <executions>
             <execution>
               <id>attach-javadocs</id>
@@ -381,7 +381,7 @@
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>build-helper-maven-plugin</artifactId>
-          <version>3.0.0</version>
+          <version>3.2.0</version>
           <executions>
             <execution>
               <phase>generate-sources</phase>
@@ -401,7 +401,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-source-plugin</artifactId>
-          <version>3.2.0</version>
+          <version>3.2.1</version>
           <executions>
             <execution>
               <id>attach-sources</id>
@@ -421,7 +421,7 @@
         <plugin>
           <groupId>com.amashchenko.maven.plugin</groupId>
           <artifactId>gitflow-maven-plugin</artifactId>
-          <version>1.14.0</version>
+          <version>1.16.0</version>
           <configuration>
             <gitFlowConfig>
               <productionBranch>master</productionBranch>