diff --git a/src/main/java/de/neemann/digital/builder/ExpressionToFileExporter.java b/src/main/java/de/neemann/digital/builder/ExpressionToFileExporter.java
index 4c12736bf..43b4472fc 100644
--- a/src/main/java/de/neemann/digital/builder/ExpressionToFileExporter.java
+++ b/src/main/java/de/neemann/digital/builder/ExpressionToFileExporter.java
@@ -1,6 +1,7 @@
 package de.neemann.digital.builder;
 
 import de.neemann.digital.builder.jedec.FuseMapFillerException;
+import de.neemann.digital.lang.Lang;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -80,7 +81,7 @@ public class ExpressionToFileExporter {
             try {
                 file = p.execute(file);
             } catch (IOException e) {
-                throw new IOException("post process error in " + p.toString(), e);
+                throw new IOException(Lang.get("err_postProcessErrorIn_N0", p.toString()), e);
             }
     }
 
diff --git a/src/main/java/de/neemann/digital/builder/tt2/StartFitter.java b/src/main/java/de/neemann/digital/builder/tt2/StartFitter.java
index dfcd46e8a..e824abada 100644
--- a/src/main/java/de/neemann/digital/builder/tt2/StartFitter.java
+++ b/src/main/java/de/neemann/digital/builder/tt2/StartFitter.java
@@ -4,6 +4,7 @@ import de.neemann.digital.builder.ExpressionToFileExporter;
 import de.neemann.digital.core.element.Keys;
 import de.neemann.digital.gui.Main;
 import de.neemann.digital.gui.Settings;
+import de.neemann.digital.lang.Lang;
 
 import javax.swing.*;
 import java.io.File;
@@ -21,7 +22,7 @@ public class StartFitter implements ExpressionToFileExporter.PostProcess {
     /**
      * Creates a new instance
      *
-     * @param parent     the parent dialog
+     * @param parent the parent dialog
      */
     public StartFitter(JDialog parent) {
         this.parent = parent;
@@ -42,7 +43,7 @@ public class StartFitter implements ExpressionToFileExporter.PostProcess {
 
         String message = execute.start();
 
-        SwingUtilities.invokeLater(() -> JOptionPane.showMessageDialog(parent, message));
+        SwingUtilities.invokeLater(() -> JOptionPane.showMessageDialog(parent, message, Lang.get("msg_fitterResult"), JOptionPane.INFORMATION_MESSAGE));
 
         return Main.checkSuffix(file, "jed");
     }
@@ -54,6 +55,6 @@ public class StartFitter implements ExpressionToFileExporter.PostProcess {
 
     @Override
     public String toString() {
-        return "External fitter to create a JEDEC file";
+        return Lang.get("msg_startExternalFitter");
     }
 }
diff --git a/src/main/resources/lang/lang_de.xml b/src/main/resources/lang/lang_de.xml
index 76b117077..02d2ffed9 100644
--- a/src/main/resources/lang/lang_de.xml
+++ b/src/main/resources/lang/lang_de.xml
@@ -428,10 +428,11 @@ Zur Analyse können Sie die Schaltung im Gatterschrittmodus ausführen.</string>
     <string name="err_openingDocumentation">Browser konnte nicht geöffnet werden.</string>
     <string name="err_splitterDoesNotSupportHighZInputs">Der Splitter unterstützt keine HighZ Eingänge! Verwenden Sie einen PullUp- oder PullDown-Widerstand</string>
     <string name="err_splitterAllowsOnlyOneHighZInput">Ein Splitter der hochohmige Eingänge erlaubt, kann nur einen Eingang haben!</string>
-    <string name="err_couldNotCreateFolder_N0">Konnte den Order '{0}' nicht erzeugen!</string>
+    <string name="err_couldNotCreateFolder_N0">Konnte den Order &quot;{0}&quot; nicht erzeugen!</string>
     <string name="err_switchHasNoNet">Ein Schalter kann nicht nur mit Eingängen verbunden werden.</string>
     <string name="err_file_N0_ExistsTwiceBelow_N1">Die Datei {0} existiert mehrfach unter {1}</string>
     <string name="err_couldNotFindIncludedFile_N0">Die Datei {0} konnte nicht gefunden werden.</string>
+    <string name="err_postProcessErrorIn_N0">Fehler im Bearbeitungsschritt &quot;{0}&quot;.</string>
 
     <string name="key_AddrBits">Adress-Bits</string>
     <string name="key_AddrBits_tt">Anzahl der Adress-Bits die verwendet werden.</string>
@@ -702,6 +703,9 @@ Die Icons stammen aus dem Tango Desktop Project.</string>
     <string name="msg_clipboardContainsNoImportableData">In der Zwischenablage befinden sich keine importierbaren Daten!</string>
     <string name="msg_selectAnEmptyFolder">Wählen Sie einen leeren Ordner aus!</string>
     <string name="msg_errorWhileExecutingTests_N0">Während der Ausführung der Tests {0} ist ein Fehler aufgetreten!</string>
+    <string name="msg_fitterResult">Meldung vom externen Fitter</string>
+    <string name="msg_startExternalFitter">Starten des externen Fitters</string>
+
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>
     <string name="rot_180">180°</string>
diff --git a/src/main/resources/lang/lang_en.xml b/src/main/resources/lang/lang_en.xml
index 1c3fd9e8a..5a8e5d251 100644
--- a/src/main/resources/lang/lang_en.xml
+++ b/src/main/resources/lang/lang_en.xml
@@ -414,10 +414,11 @@ To analyse you can run the circuit in single gate step mode.</string>
     <string name="err_openingDocumentation">Could not open the browser.</string>
     <string name="err_splitterDoesNotSupportHighZInputs">The splitter does not support high z inputs! Use a pull up or pull down resisitor.</string>
     <string name="err_splitterAllowsOnlyOneHighZInput">A splitter which allows high z inputs can only have one input!</string>
-    <string name="err_couldNotCreateFolder_N0">Could not create folder '{0}'!</string>
+    <string name="err_couldNotCreateFolder_N0">Could not create folder &quot;{0}&quot;!</string>
     <string name="err_switchHasNoNet">It is not allowed to connect only inputs to a switch.</string>
     <string name="err_file_N0_ExistsTwiceBelow_N1">The file {0} exists multiple times below {1}.</string>
     <string name="err_couldNotFindIncludedFile_N0">Could not find the file {0}.</string>
+    <string name="err_postProcessErrorIn_N0">Error during execution of &quot;{0}&quot;.</string>
 
     <string name="key_AddrBits">Address Bits</string>
     <string name="key_AddrBits_tt">Number of address bits used.</string>
@@ -688,6 +689,9 @@ The icons are taken from the Tango Desktop Project.</string>
     <string name="msg_clipboardContainsNoImportableData">The clipboard contains no importable data!</string>
     <string name="msg_selectAnEmptyFolder">Select an empty folder!</string>
     <string name="msg_errorWhileExecutingTests_N0">During the execution of the tests {0} an error has occurred!</string>
+    <string name="msg_fitterResult">Message from the external fitter</string>
+    <string name="msg_startExternalFitter">Execution of external fitter</string>
+
     <string name="ok">Ok</string>
     <string name="rot_0">0°</string>
     <string name="rot_180">180°</string>