diff --git a/src/dk.gov.oiosi/dk.gov.oiosi.csproj b/src/dk.gov.oiosi/dk.gov.oiosi.csproj
index 4f5149d87e466fe68a241522c782d3ec82dc437d..779ffed754e54395e14c8a7184450c38ea34672f 100644
--- a/src/dk.gov.oiosi/dk.gov.oiosi.csproj
+++ b/src/dk.gov.oiosi/dk.gov.oiosi.csproj
@@ -74,38 +74,37 @@
     </Reference>
     <Reference Include="IKVM.OpenJDK.Charsets, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.OpenJDK.Charsets.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.Charsets.dll</HintPath>
     </Reference>
     <Reference Include="IKVM.OpenJDK.Core, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.OpenJDK.Core.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.Core.dll</HintPath>
     </Reference>
-    <Reference Include="IKVM.OpenJDK.Text, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
+    <Reference Include="IKVM.OpenJDK.Localedata">
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.Localedata.dll</HintPath>
+    </Reference>
+    <Reference Include="IKVM.OpenJDK.Text, Version=8.1.5717.0, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.OpenJDK.Text.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.Text.dll</HintPath>
     </Reference>
-    <Reference Include="IKVM.OpenJDK.Util, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
+    <Reference Include="IKVM.OpenJDK.Util, Version=8.1.5717.0, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.OpenJDK.Util.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.Util.dll</HintPath>
     </Reference>
-    <Reference Include="IKVM.OpenJDK.XML.API, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
+    <Reference Include="IKVM.OpenJDK.XML.API, Version=8.1.5717.0, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.OpenJDK.XML.API.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.OpenJDK.XML.API.dll</HintPath>
     </Reference>
     <Reference Include="IKVM.Runtime, Version=7.2.4630.5, Culture=neutral, PublicKeyToken=13235d27fcbfff58, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\IKVM.Runtime.dll</HintPath>
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\IKVM.Runtime.dll</HintPath>
     </Reference>
     <Reference Include="Novell.Directory.Ldap, Version=2.1.10.0, Culture=neutral">
       <SpecificVersion>False</SpecificVersion>
       <HintPath>..\..\lib\Novell.Directory.Ldap.dll</HintPath>
     </Reference>
-    <Reference Include="saxon9he">
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\saxon9he.dll</HintPath>
-    </Reference>
-    <Reference Include="saxon9he-api, Version=9.5.1.8, Culture=neutral, PublicKeyToken=e1fdd002d5083fe6, processorArchitecture=MSIL">
-      <HintPath>..\..\packages\Saxon-HE.9.5.1.8\lib\net35\saxon9he-api.dll</HintPath>
-      <Private>True</Private>
+    <Reference Include="saxon-he-api-10.3, Version=10.3.0.0, Culture=neutral, PublicKeyToken=e1fdd002d5083fe6, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Saxon-HE.10.3.0\lib\net40\saxon-he-api-10.3.dll</HintPath>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.configuration" />
diff --git a/src/dk.gov.oiosi/packages.config b/src/dk.gov.oiosi/packages.config
index 5485d5110c75583b1c2dd63e6eec22e7e1cc0bde..9571d9cd1b8bfd977c41ef822188447b62200c46 100644
--- a/src/dk.gov.oiosi/packages.config
+++ b/src/dk.gov.oiosi/packages.config
@@ -2,5 +2,5 @@
 <packages>
   <package id="BouncyCastle" version="1.8.9" targetFramework="net462" />
   <package id="Brutal.Dev.StrongNameSigner" version="2.1.3" targetFramework="net462" />
-  <package id="Saxon-HE" version="9.5.1.8" targetFramework="net462" />
+  <package id="Saxon-HE" version="10.3.0" targetFramework="net462" />
 </packages>
\ No newline at end of file
diff --git a/src/dk.gov.oiosi/xml/schematron/SchematronValidator.cs b/src/dk.gov.oiosi/xml/schematron/SchematronValidator.cs
index 6c7f2c6e96cc00d2a55ab7adc99b0cbedf8b88e6..9185760d75430eedf2f0507a827a6ee14995ec56 100644
--- a/src/dk.gov.oiosi/xml/schematron/SchematronValidator.cs
+++ b/src/dk.gov.oiosi/xml/schematron/SchematronValidator.cs
@@ -188,7 +188,7 @@ namespace dk.gov.oiosi.xml.schematron
 
                             Processor processor = new Processor();
                             XsltCompiler compiler = processor.NewXsltCompiler();
-                            Serializer serializer = new Serializer();
+                            Serializer serializer = processor.NewSerializer();
 
                             try
                             {
@@ -432,9 +432,9 @@ namespace dk.gov.oiosi.xml.schematron
                             Processor processor = new Processor();
                             XsltCompiler compiler = processor.NewXsltCompiler();
                             Uri uri = new Uri("file://" + compiledXslt.FileInfo.Directory.FullName);
-                            compiler.ErrorList = new List<object>();
+                            
                             compiler.BaseUri = uri;
-                            Serializer serializer = new Serializer();
+                            Serializer serializer = processor.NewSerializer();
 
                             try
                             {