diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index dd03b27b..562b5c18 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -12,11 +12,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v6
-    - uses: actions/setup-java@v5 # the log states the default ~/.m2/toolchains.xml is being created pointing to the JDK
+    - uses: actions/checkout@v3
+    - uses: actions/setup-java@v3 # the log states the default ~/.m2/toolchains.xml is being created pointing to the JDK
       with:
         distribution: 'adopt' # for latest JDKs use temurin https://blog.adoptopenjdk.net/2021/08/goodbye-adoptopenjdk-hello-adoptium/
-        java-version: '17'
+        java-version: '11'
         cache: 'maven' #cache/restore any dependencies to improve the workflow execution time
     - name: Build with Maven
       run: mvn -B package --file pom.xml
\ No newline at end of file
diff --git a/Mustang-CLI/pom.xml b/Mustang-CLI/pom.xml
index 789676f9..e91e41c8 100644
--- a/Mustang-CLI/pom.xml
+++ b/Mustang-CLI/pom.xml
@@ -13,7 +13,7 @@
     <packaging>jar</packaging>
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.release>${java.version}</maven.compiler.release>
+        <maven.compiler.release>11</maven.compiler.release>
     </properties>
     <dependencies>
         <!-- compile dependencies -->
@@ -118,8 +118,8 @@
                     <!-- http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven
                              mvn clean compile assembly:single -->
                     <!-- or whatever version you use -->
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <source>11</source>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -209,7 +209,7 @@
                         <configuration>
                             <toolchains>
                                 <jdk>
-                                    <version>${java.version}</version>
+                                    <version>11</version>
                                     <vendor>adopt</vendor>
                                 </jdk>
                             </toolchains>
diff --git a/library/pom.xml b/library/pom.xml
index aacb32ae..67de4f9c 100644
--- a/library/pom.xml
+++ b/library/pom.xml
@@ -44,7 +44,7 @@
         <github.global.server>github</github.global.server>
         <additionalparam>-Xdoclint:none</additionalparam>
         <!-- Skip error check for javadoc -->
-        <maven.compiler.release>${java.version}</maven.compiler.release>
+        <maven.compiler.release>11</maven.compiler.release>
         <maven.deploy.skip>true</maven.deploy.skip><!-- do deploy to maven central, parent project does not and inherits -->
     </properties>
     <dependencies>
@@ -149,12 +149,6 @@
             <version>${version.org.glassfish.jaxb}</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.slf4j</groupId>
-            <artifactId>slf4j-simple</artifactId>
-            <version>${version.org.slf4j}</version>
-            <scope>test</scope>
-        </dependency>
     </dependencies>
     <build>
         <plugins>
@@ -175,8 +169,8 @@
                     <!-- http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven
                         mvn clean compile assembly:single -->
                     <!-- or whatever version you use -->
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <source>11</source>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -337,7 +331,7 @@
                         <configuration>
                             <toolchains>
                                 <jdk>
-                                    <version>${java.version}</version>
+                                    <version>11</version>
                                     <vendor>adopt</vendor>
                                 </jdk>
                             </toolchains>
diff --git a/library/src/main/java/org/mustangproject/CII/CIIToUBL.java b/library/src/main/java/org/mustangproject/CII/CIIToUBL.java
index 8480e81b..816f6992 100644
--- a/library/src/main/java/org/mustangproject/CII/CIIToUBL.java
+++ b/library/src/main/java/org/mustangproject/CII/CIIToUBL.java
@@ -3,7 +3,7 @@ package org.mustangproject.CII;
 import java.io.File;
 import java.io.Serializable;
 
-import com.helger.diagnostics.error.list.ErrorList;
+import com.helger.commons.error.list.ErrorList;
 import com.helger.en16931.cii2ubl.CIIToUBL23Converter;
 import com.helger.ubl23.UBL23Marshaller;
 
diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
index 3e594830..dfdeac49 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
@@ -551,13 +551,9 @@ public class ZUGFeRDInvoiceImporter {
 		NodeList lineDueNodes = (NodeList) xpr.evaluate(getDocument(), XPathConstants.NODESET);
 		BigDecimal duePayableAmount = null;
 		if (lineDueNodes.getLength() > 0) {
-			String duePayableAmountStr=XMLTools.trimOrNull(lineDueNodes.item(0));
-			if (duePayableAmountStr!=null) {
-			  // Always set it, because it is used in the calculation below
-				duePayableAmount = new BigDecimal(duePayableAmountStr);
-				if (zpp instanceof CalculatedInvoice) {
-					((CalculatedInvoice) zpp).setDuePayable(duePayableAmount);
-				}
+			duePayableAmount = new BigDecimal(XMLTools.trimOrNull(lineDueNodes.item(0)));
+			if (zpp instanceof CalculatedInvoice) {
+				((CalculatedInvoice) zpp).setDuePayable(duePayableAmount);
 			}
 		}
 
diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDVisualizer.java b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDVisualizer.java
index 357a3b87..cf9551aa 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDVisualizer.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDVisualizer.java
@@ -20,7 +20,7 @@
  */
 package org.mustangproject.ZUGFeRD;
 
-import com.helger.base.io.stream.StreamHelper;
+import com.helger.commons.io.stream.StreamHelper;
 import javax.xml.XMLConstants;
 import javax.xml.parsers.ParserConfigurationException;
 import org.apache.commons.io.IOUtils;
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/DXTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/DXTest.java
index 04ed7fa0..5e4a5316 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/DXTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/DXTest.java
@@ -335,8 +335,10 @@ public class DXTest extends MustangReaderTestCase {
 		zf2p.setProfile(Profiles.getByName(EStandard.despatchadvice,"Pilot",1));
 		zf2p.generateXML(i);
 		String theXML = new String(zf2p.getXML(), StandardCharsets.UTF_8);
-		try(BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML))) {
+		try {
+			BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML));
 			writer.write(theXML);
+			writer.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/FXTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/FXTest.java
index 1eeed4e6..fbe986b3 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/FXTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/FXTest.java
@@ -62,8 +62,10 @@ public class FXTest extends TestCase {
 		assertThat(theXML).valueByXPath("//*[local-name()='DuePayableAmount']")
 				.asDouble()
 				.isEqualTo(1);
-		try(BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML))) {
+		try {
+			BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML));
 			writer.write(theXML);
+			writer.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/UBLTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/UBLTest.java
index 0ecc0339..522ff9bd 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/UBLTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/UBLTest.java
@@ -30,10 +30,8 @@ import java.text.ParseException;
 import java.util.Date;
 
 import org.assertj.core.api.Assertions;
-import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Order;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.TestMethodOrder;
 import org.mustangproject.BankDetails;
 import org.mustangproject.CII.CIIToUBL;
 import org.mustangproject.Contact;
@@ -44,7 +42,6 @@ import org.mustangproject.TradeParty;
 
 import javax.xml.xpath.XPathExpressionException;
 
-@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
 public class UBLTest extends ResourceCase {
 	final String TARGET_XML = "./target/testout-1Lieferschein.xml";
 
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/XRTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/XRTest.java
index 495a0563..3109f1b7 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/XRTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/XRTest.java
@@ -81,8 +81,10 @@ public class XRTest extends TestCase {
 		assertThat(theXML).valueByXPath("//*[local-name()='DuePayableAmount']")
 			.asDouble()
 			.isEqualTo(1);
-		try(BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML))) {
+		try {
+			BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML));
 			writer.write(theXML);
+			writer.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
@@ -132,8 +134,10 @@ public class XRTest extends TestCase {
 		assertThat(theXML).valueByXPath("//*[local-name()='DuePayableAmount']")
 			.asDouble()
 			.isEqualTo(1);
-		try(BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_EDGE_XML))) {
+		try {
+			BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_EDGE_XML));
 			writer.write(theXML);
+			writer.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
@@ -247,8 +251,10 @@ public class XRTest extends TestCase {
 		assertThat(theXML).valueByXPath("//*[local-name()='DuePayableAmount']")
 			.asDouble()
 			.isEqualTo(1);
-		try(BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML))) {
+		try {
+			BufferedWriter writer = new BufferedWriter(new FileWriter(TARGET_XML));
 			writer.write(theXML);
+			writer.close();
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
index 3cddc296..3408b9a0 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
@@ -309,7 +309,9 @@ public class ZF2PushTest extends TestCase {
 		String number = "123";
 		String priceStr = "3.00";
 		BigDecimal price = new BigDecimal(priceStr);
-		try(InputStream SOURCE_PDF = this.getClass().getResourceAsStream("/MustangGnuaccountingBeispielRE-20170509_505blanko.pdf")) {
+		try {
+			InputStream SOURCE_PDF = this.getClass().getResourceAsStream("/MustangGnuaccountingBeispielRE-20170509_505blanko.pdf");
+
 			ZUGFeRDExporterFromA1 ze = new ZUGFeRDExporterFromA1();
 			ze.ignorePDFAErrors().load(SOURCE_PDF);
 			ze.setProfile(Profiles.getByName("Extended"));
@@ -357,7 +359,7 @@ public class ZF2PushTest extends TestCase {
 
 
 	/***
-	 * you can activate intra community supply on item level
+	 * you can activate intra community suppliy on item level
 	 */
 	public void testIntraCommunitySupplyItemExport() {
 
diff --git a/pom.xml b/pom.xml
index 84d1378b..ea91c007 100644
--- a/pom.xml
+++ b/pom.xml
@@ -28,8 +28,7 @@
         <github.global.server>github</github.global.server>
         <additionalparam>-Xdoclint:none</additionalparam>
         <!-- Skip error check for javadoc -->
-        <java.version>17</java.version>
-        <maven.compiler.release>17</maven.compiler.release>
+        <maven.compiler.release>11</maven.compiler.release>
         <maven.deploy.skip>true</maven.deploy.skip><!-- prevent this to be deployed to maven central as "core",
         we only want submodules, see also https://stackoverflow.com/questions/7446599/how-to-deploy-only-the-sub-modules-using-maven-deploy-->
 
@@ -48,40 +47,40 @@
 
             First the versions for plugins, then those for libraries.
          -->
-        <version.org.apache.maven.plugins.maven-compiler-plugin>3.15.0</version.org.apache.maven.plugins.maven-compiler-plugin><!-- from 3.13.0 -->
-        <version.org.apache.maven.plugins.maven-deploy-plugin>3.1.4</version.org.apache.maven.plugins.maven-deploy-plugin><!-- from 3.0.0-M1 -->
-        <version.org.apache.maven.plugins.maven-gpg-plugin>3.2.8</version.org.apache.maven.plugins.maven-gpg-plugin><!-- from 1.6 -->
-        <version.org.apache.maven.plugins.maven-jar-plugin>3.5.0</version.org.apache.maven.plugins.maven-jar-plugin><!-- from 3.2.0, 3.4.2 -->
-        <version.org.apache.maven.plugins.maven-javadoc-plugin>3.12.0</version.org.apache.maven.plugins.maven-javadoc-plugin><!-- from 3.0.1 -->
-        <version.org.apache.maven.plugins.maven-release-plugin>3.3.1</version.org.apache.maven.plugins.maven-release-plugin><!-- from 2.5.3 -->
-        <version.org.apache.maven.plugins.maven-resources-plugin>3.5.0</version.org.apache.maven.plugins.maven-resources-plugin><!-- from 3.1.0 -->
-        <version.org.apache.maven.plugins.maven-shade-plugin>3.6.1</version.org.apache.maven.plugins.maven-shade-plugin><!-- from 2.4.3, 3.5.3 -->
-        <version.org.apache.maven.plugins.maven-source-plugin>3.4.0</version.org.apache.maven.plugins.maven-source-plugin><!-- from 3.2.1, 3.3.1 -->
-        <version.org.apache.maven.plugins.maven-surefire-plugin>3.5.5</version.org.apache.maven.plugins.maven-surefire-plugin><!-- from 3.5.3 -->
-        <version.org.apache.maven.plugins.maven-toolchains-plugin>3.2.0</version.org.apache.maven.plugins.maven-toolchains-plugin><!-- from 3.1.0 -->
-        <version.org.apache.maven.scm>2.2.1</version.org.apache.maven.scm><!-- from 1.9.5 -->
+        <version.org.apache.maven.plugins.maven-compiler-plugin>3.13.0</version.org.apache.maven.plugins.maven-compiler-plugin><!-- from 2.3.2, 3.13.0 -->
+        <version.org.apache.maven.plugins.maven-deploy-plugin>3.0.0-M1</version.org.apache.maven.plugins.maven-deploy-plugin><!-- from 3.0.0-M1 -->
+        <version.org.apache.maven.plugins.maven-gpg-plugin>1.6</version.org.apache.maven.plugins.maven-gpg-plugin><!-- from 1.6 -->
+        <version.org.apache.maven.plugins.maven-jar-plugin>3.4.2</version.org.apache.maven.plugins.maven-jar-plugin><!-- from 3.2.0, 3.4.2 -->
+        <version.org.apache.maven.plugins.maven-javadoc-plugin>3.0.1</version.org.apache.maven.plugins.maven-javadoc-plugin><!-- from 3.0.1 -->
+        <version.org.apache.maven.plugins.maven-release-plugin>2.5.3</version.org.apache.maven.plugins.maven-release-plugin><!-- from 2.5.3 -->
+        <version.org.apache.maven.plugins.maven-resources-plugin>3.1.0</version.org.apache.maven.plugins.maven-resources-plugin><!-- from 3.1.0 -->
+        <version.org.apache.maven.plugins.maven-shade-plugin>3.5.3</version.org.apache.maven.plugins.maven-shade-plugin><!-- from 2.4.3, 3.5.3 -->
+        <version.org.apache.maven.plugins.maven-source-plugin>3.3.1</version.org.apache.maven.plugins.maven-source-plugin><!-- from 3.2.1, 3.3.1 -->
+        <version.org.apache.maven.plugins.maven-surefire-plugin>3.5.3</version.org.apache.maven.plugins.maven-surefire-plugin>
+        <version.org.apache.maven.plugins.maven-toolchains-plugin>3.1.0</version.org.apache.maven.plugins.maven-toolchains-plugin><!-- from 3.1.0 -->
+        <version.org.apache.maven.scm>1.9.5</version.org.apache.maven.scm>
         <version.org.codehaus.mojo>1.0.0</version.org.codehaus.mojo>
-        <version.com.helger.maven.schematron>9.1.1</version.com.helger.maven.schematron><!-- from 8.0.0 -->
+        <version.com.helger.maven>8.0.0</version.com.helger.maven>
         <version.org.sonatype.plugins>1.7.0</version.org.sonatype.plugins>
 
-        <version.ch.qos.logback>1.5.32</version.ch.qos.logback><!-- from 1.5.16, 1.5.18 -->
-        <version.com.fasterxml.jackson.core>2.21.1</version.com.fasterxml.jackson.core><!-- from 2.17.1, 2.17.3 -->
-        <version.com.helger.en16931-cii2ubl>3.1.7</version.com.helger.en16931-cii2ubl><!-- from 2.3.0, 2.3.1 -->
-        <version.com.helger.schematron>9.1.1</version.com.helger.schematron><!-- from 8.0.0, 8.0.6 -->
-        <version.commons-cli>1.11.0</version.commons-cli><!-- from 1.8.0, 1.10.0 -->
-        <version.commons-io>2.21.0</version.commons-io><!-- from 2.16.1, 2.20.0 -->
-        <version.jakarta.xml.bind>4.0.5</version.jakarta.xml.bind><!-- from 4.0.2 -->
-        <version.net.sf.saxon>12.9</version.net.sf.saxon><!-- from 12.4, 12.8 -->
-        <version.org.apache.pdfbox>3.0.7</version.org.apache.pdfbox><!-- from 3.0.6 -->
+        <version.ch.qos.logback>1.5.18</version.ch.qos.logback><!-- from 1.5.16 -->
+        <version.com.fasterxml.jackson.core>2.17.3</version.com.fasterxml.jackson.core><!-- from 2.17.1 -->
+        <version.com.helger.en16931-cii2ubl>2.3.1</version.com.helger.en16931-cii2ubl><!-- from 2.3.0 -->
+        <version.com.helger.schematron>8.0.6</version.com.helger.schematron><!-- from 8.0.0 -->
+        <version.commons-cli>1.10.0</version.commons-cli><!-- from 1.8.0 -->
+        <version.commons-io>2.20.0</version.commons-io><!-- from 2.16.1 -->
+        <version.jakarta.xml.bind>4.0.2</version.jakarta.xml.bind>
+        <version.net.sf.saxon>12.8</version.net.sf.saxon><!-- from 12.4 -->
+        <version.org.apache.pdfbox>3.0.7</version.org.apache.pdfbox>
         <version.org.apache.xmlgraphics>2.11</version.org.apache.xmlgraphics><!-- from 2.10 -->
         <version.org.codehaus.janino>3.1.12</version.org.codehaus.janino><!-- from 3.1.7 -->
-        <version.org.dom4j>2.2.0</version.org.dom4j><!-- from 2.1.4, 2.1.5 -->
-        <version.org.glassfish.jaxb>4.0.7</version.org.glassfish.jaxb><!-- from 4.0.5 -->
+        <version.org.dom4j>2.1.5</version.org.dom4j><!-- from 2.1.4 -->
+        <version.org.glassfish.jaxb>4.0.5</version.org.glassfish.jaxb>
         <version.org.junit>5.13.4</version.org.junit><!-- from 5.10.2 -->
         <version.org.skyscreamer>2.0-rc1</version.org.skyscreamer>
         <version.org.slf4j>2.0.17</version.org.slf4j><!-- from 2.0.9, 2.0.12  -->
-        <version.org.verapdf>1.28.2</version.org.verapdf><!-- from 1.26.2, 1.26.5 -->
-        <version.org.xmlunit>2.11.0</version.org.xmlunit><!-- from 2.10.0, 2.10.3 -->
+        <version.org.verapdf>1.26.5</version.org.verapdf><!-- from 1.26.2 -->
+        <version.org.xmlunit>2.10.3</version.org.xmlunit><!-- from 2.10.0 -->
     </properties>
 
     <build>
@@ -245,7 +244,7 @@
                         <configuration>
                             <toolchains>
                                 <jdk>
-                                    <version>17</version>
+                                    <version>11</version>
                                     <vendor>adopt</vendor>
                                 </jdk>
                             </toolchains>
diff --git a/validator/pom.xml b/validator/pom.xml
index fb1dc486..65d797aa 100644
--- a/validator/pom.xml
+++ b/validator/pom.xml
@@ -26,7 +26,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.deploy.skip>false</maven.deploy.skip><!-- do deploy to maven central, parent project does not and inherits -->
-        <maven.compiler.release>${java.version}</maven.compiler.release>
+        <maven.compiler.release>11</maven.compiler.release>
     </properties>
     <dependencies>
         <!-- compile dependencies -->
@@ -141,8 +141,8 @@
                     <!-- http://stackoverflow.com/questions/574594/how-can-i-create-an-executable-jar-with-dependencies-using-maven
                              mvn clean compile assembly:single -->
                     <!-- or whatever version you use -->
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
+                    <source>11</source>
+                    <target>11</target>
                 </configuration>
             </plugin>
             <!-- /ZUV -->
@@ -273,7 +273,7 @@
                         <configuration>
                             <toolchains>
                                 <jdk>
-                                    <version>${java.version}</version>
+                                    <version>11</version>
                                     <vendor>adopt</vendor>
                                 </jdk>
                             </toolchains>
@@ -293,7 +293,7 @@
                     <plugin>
                         <groupId>com.helger.maven</groupId>
                         <artifactId>ph-schematron-maven-plugin</artifactId>
-                        <version>${version.com.helger.maven.schematron}</version>
+                        <version>${version.com.helger.maven}</version>
                         <configuration>
                             <schematronDirectory>${basedir}/src/main/resources/schematron</schematronDirectory>
                             <xsltDirectory>${basedir}/src/main/resources/xslt</xsltDirectory>
diff --git a/validator/src/main/java/org/mustangproject/validator/PDFValidator.java b/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
index 5d0d348d..993a2d0a 100644
--- a/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
+++ b/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
@@ -113,7 +113,7 @@ public class PDFValidator extends Validator {
 			ItemDetails itemDetails = ItemDetails.fromValues(pdfFilename);
 			inputStream.mark(Integer.MAX_VALUE);
 			processorResult = processor.process(itemDetails, inputStream);
-			pdfReport = processorResult.getValidationResults().get(0).toString().replaceAll(
+			pdfReport = processorResult.getValidationResult().toString().replaceAll(
 				"<\\?xml version=\"1\\.0\" encoding=\"utf-8\"\\?>",
 				""
 			);
@@ -330,11 +330,11 @@ public class PDFValidator extends Validator {
 		//end
 
 		final long endTime = Calendar.getInstance().getTimeInMillis();
-		if (!processorResult.getValidationResults().get (0).isCompliant()) {
+		if (!processorResult.getValidationResult().isCompliant()) {
 			context.setInvalid();
 		}
 
-		PDFAFlavour pdfaFlavourFromValidationResult = processorResult.getValidationResults().get (0).getPDFAFlavour();
+		PDFAFlavour pdfaFlavourFromValidationResult = processorResult.getValidationResult().getPDFAFlavour();
 		if (Arrays.stream(PDF_A_3_FLAVOURS)
 			.noneMatch(pdfaFlavourFromValidationResult::equals)) {
 			context.addResultItem(
diff --git a/validator/src/main/java/org/mustangproject/validator/ZUGFeRDValidator.java b/validator/src/main/java/org/mustangproject/validator/ZUGFeRDValidator.java
index f71b79dd..e6a319a4 100644
--- a/validator/src/main/java/org/mustangproject/validator/ZUGFeRDValidator.java
+++ b/validator/src/main/java/org/mustangproject/validator/ZUGFeRDValidator.java
@@ -24,15 +24,15 @@ import org.dom4j.DocumentException;
 import org.dom4j.DocumentHelper;
 import org.dom4j.io.OutputFormat;
 import org.dom4j.io.XMLWriter;
-import org.mustangproject.XMLTools;
 import org.mustangproject.util.ByteArraySearcher;
+import org.mustangproject.XMLTools;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.xml.sax.InputSource;
 
-import com.helger.base.io.stream.StreamHelper;
+import com.helger.commons.io.stream.StreamHelper;
 
 import jakarta.xml.bind.DatatypeConverter;