diff --git a/developer/src/kmc-convert/src/keylayout-to-kmn/keylayout-to-kmn-converter.ts b/developer/src/kmc-convert/src/keylayout-to-kmn/keylayout-to-kmn-converter.ts
index 36c195cd85..bd941358dd 100644
--- a/developer/src/kmc-convert/src/keylayout-to-kmn/keylayout-to-kmn-converter.ts
+++ b/developer/src/kmc-convert/src/keylayout-to-kmn/keylayout-to-kmn-converter.ts
@@ -103,11 +103,6 @@ export class KeylayoutToKmnConverter {
       return null;
     }
 
-    if (outputFilename === null) {
-      this.callbacks.reportMessage(ConverterMessages.Error_OutputFilenameIsRequired());
-      return null;
-    }
-
     const KeylayoutReader = new KeylayoutFileReader(this.callbacks/*, this.options*/);
     const jsonO: Keylayout.KeylayoutXMLSourceFile = KeylayoutReader.read(inputFilename);
 
@@ -120,9 +115,7 @@ export class KeylayoutToKmnConverter {
       return null;
     }
 
-    outputFilename = outputFilename ?? inputFilename.replace(/\.keylayout$/, '.kmn');
-
-    const outArray: ProcessedData = await this.convert(jsonO, outputFilename);
+    const outArray: ProcessedData = await this.convert(jsonO, inputFilename);
 
     const kmnFileWriter = new KmnFileWriter(this.callbacks, this.options);
 
@@ -130,7 +123,7 @@ export class KeylayoutToKmnConverter {
     const outUint8: Uint8Array = kmnFileWriter.write(outArray);
     const result: ConverterToKmnResult = {
       artifacts: {
-        kmn: { data: outUint8, filename: outputFilename }
+        kmn: { data: outUint8, filename: outArray.kmnFilename }
       }
     };
     return result;
@@ -141,10 +134,14 @@ export class KeylayoutToKmnConverter {
    * @param  jsonObj containing filename, behaviour and rules of a json object
    * @return an ProcessedData containing all data ready to print out
    */
-  private convert(jsonObj: any, outputfilename: string): ProcessedData {
-    const modifierBehavior: string[][] = [];           // modifier for each behaviour
-    const rules: Rule[] = [];                          // an array of data for a kmn rule
+  private convert(jsonObj: any, inputfilename: string): ProcessedData {
+    // modifiers for each behaviour
+    const modifierBehavior: string[][] = [];
 
+    // an array of data for a kmn rule
+    const rules: Rule[] = [];
+
+    // dataObject for all relevant data
     const dataObject: ProcessedData = {
       keylayoutFilename: "",
       kmnFilename: "",
@@ -152,11 +149,10 @@ export class KeylayoutToKmnConverter {
       arrayOfRules: []
     };
 
-    if ((jsonObj !== null) && (jsonObj.hasOwnProperty("keyboard"))) {
-      dataObject.keylayoutFilename = outputfilename.replace(/\.kmn$/, '.keylayout');
-      dataObject.kmnFilename = outputfilename;
-      dataObject.arrayOfModifiers = modifierBehavior;  // ukelele uses behaviours e.g. 18 modifiersCombinations in 8 KeyMapSelect(behaviors)
-      dataObject.arrayOfRules = rules;
+    if ((jsonObj === null) || (!jsonObj.hasOwnProperty("keyboard"))) {
+      this.callbacks.reportMessage(ConverterMessages.Error_UnableToRead({ inputFilename: inputfilename }));
+      return dataObject;
+    } else {
 
       // create an array of modifier combinations and store in dataObject
       for (let j = 0; j < jsonObj.keyboard.modifierMap.keyMapSelect.length; j++) {
@@ -166,17 +162,19 @@ export class KeylayoutToKmnConverter {
         }
         modifierBehavior.push(singleModifierSet);
       }
+
+      // fill dataObject with filenames, behaviours and (initialized) rules
+      dataObject.keylayoutFilename = inputfilename;
+      dataObject.kmnFilename = inputfilename.replace(/\.kkeylayoutn$/, '.kmn');;
+      dataObject.arrayOfModifiers = modifierBehavior;  // ukelele uses behaviours e.g. 18 modifiersCombinations in 8 KeyMapSelect(behaviors)
+      dataObject.arrayOfRules = rules;
+
       // fix the amount of processable keys to the maximun nr of keys of a keyMap to avoid processing more keys than defined
       KeylayoutToKmnConverter.USE_KEY_COUNT = findUsedKeysCount(jsonObj);
 
       // fill rules into arrayOfRules of dataObject
       return this.createRuleData(dataObject, jsonObj);
     }
-    else {
-      const inputFilename = dataObject.keylayoutFilename;
-      this.callbacks.reportMessage(ConverterMessages.Error_UnableToConvert({ inputFilename }));
-      return dataObject;
-    }
   }
 
   /**
diff --git a/developer/src/kmc-convert/test/keylayout-to-kmn-converter.tests.ts b/developer/src/kmc-convert/test/keylayout-to-kmn-converter.tests.ts
index c90ec696de..6b06fdbf48 100644
--- a/developer/src/kmc-convert/test/keylayout-to-kmn-converter.tests.ts
+++ b/developer/src/kmc-convert/test/keylayout-to-kmn-converter.tests.ts
@@ -107,7 +107,6 @@ describe('KeylayoutToKmnConverter', function () {
       assert.deepEqual(compilerTestCallbacks.messages[0], ConverterMessages.Error_FileNotFound({ inputFilename: null }));
     });
 
-
     it('run() should throw on null input file name and unknown output file name', async function () {
       const result = sut.run(null, 'X');
       assert.isNotNull(result);
@@ -119,38 +118,43 @@ describe('KeylayoutToKmnConverter', function () {
       const inputFilename = makePathToFixture('../data/Unavailable.keylayout');
       const result = sut.run(inputFilename, null);
       assert.isNotNull(result);
-      assert.equal(compilerTestCallbacks.messages.length, 1);
-      assert.deepEqual(compilerTestCallbacks.messages[0], ConverterMessages.Error_OutputFilenameIsRequired());
+      assert.equal(compilerTestCallbacks.messages.length, 2);
+      assert.deepEqual(compilerTestCallbacks.messages[0], ConverterMessages.Error_UnableToRead({ inputFilename }));
+      assert.equal(compilerTestCallbacks.messages[1].code, 5246984);
     });
 
-    it('run() should throw on and null output file name', async function () {
+    it('run() should return on available input file name and null output file name', async function () {
       const inputFilename = makePathToFixture('../data/Test.keylayout');
       const result = sut.run(inputFilename, null);
       assert.isNotNull(result);
-      assert.equal(compilerTestCallbacks.messages.length, 1);
-      assert.deepEqual(compilerTestCallbacks.messages[0], ConverterMessages.Error_OutputFilenameIsRequired());
+      await NodeAssert.doesNotReject(async () => sut.run(inputFilename, null));
+      assert.equal(compilerTestCallbacks.messages.length, 0);
     });
 
     it('run() should return on correct input file name and empty output file name ', async function () {
       const inputFilename = makePathToFixture('../data/Test.keylayout');
       await NodeAssert.doesNotReject(async () => sut.run(inputFilename, ''));
+      assert.equal(compilerTestCallbacks.messages.length, 0);
     });
 
     it('run() should return on correct input file name and null output file name', async function () {
       const inputFilename = makePathToFixture('../data/Test.keylayout');
       await NodeAssert.doesNotReject(async () => sut.run(inputFilename, null));
+      assert.equal(compilerTestCallbacks.messages.length, 0);
     });
 
     it('run() should return on correct input file name and given output file name ', async function () {
       const inputFilename = makePathToFixture('../data/Test.keylayout');
       const outputFilename = makePathToFixture('../data/OutputName.kmn');
       await NodeAssert.doesNotReject(async () => sut.run(inputFilename, outputFilename));
+      assert.equal(compilerTestCallbacks.messages.length, 0);
     });
 
     it('run() return on correct input file extention and unsupperted output file extention', async function () {
       const inputFilename = makePathToFixture('../data/Test.keylayout');
       const outputFilename = makePathToFixture('../data/OutputXName.B');
       await NodeAssert.doesNotReject(async () => sut.run(inputFilename, outputFilename));
+      assert.equal(compilerTestCallbacks.messages.length, 0);
     });
   });
 
@@ -206,14 +210,14 @@ describe('KeylayoutToKmnConverter', function () {
         arrayOfModifiers: [],
         arrayOfRules: [['C0', '', '', 0, 0, '', '', 0, 0, 'CAPS', 'K_A', 'A']]
       }, '');
-      assert.isTrue((convertedRule .keylayoutFilename === ''
-        && convertedRule .arrayOfModifiers.length === 0
-        && convertedRule .arrayOfRules.length === 0));
+      assert.isTrue((convertedRule.keylayoutFilename === ''
+        && convertedRule.arrayOfModifiers.length === 0
+        && convertedRule.arrayOfRules.length === 0));
     });
 
     it('should return empty array of rules on null input', async function () {
       const convertedRule = sut.convertBound.convert(null, 'ABC.kmn');
-      assert.isTrue(convertedRule .arrayOfRules.length === 0);
+      assert.isTrue(convertedRule.arrayOfRules.length === 0);
     });
   });