diff --git a/apps/renderer.c b/apps/renderer.c
index 6084b9f46a2fa15c99bb6dff7712e878c1f63410..77f25ba0b3995317e632e32935dc97063718516b 100644
--- a/apps/renderer.c
+++ b/apps/renderer.c
@@ -1041,6 +1041,22 @@ static IVAS_REND_AudioConfig ambisonicsOrderToEnum(
     return IVAS_REND_AUDIO_CONFIG_UNKNOWN;
 }
 
+#ifdef FIX_293_EXT_RENDERER_CLI
+static const CmdLnParser_Option *findOptionById(
+    const int32_t id )
+{
+    for ( int32_t i = 0; i < numCliOptions; ++i )
+    {
+        if ( cliOptions[i].id == id )
+        {
+            return &cliOptions[i];
+        }
+    }
+
+    return NULL;
+}
+#endif
+
 static bool parseInConfig(
     const char *inFormatStr,
     InputConfig *inConfig,
@@ -1128,8 +1144,13 @@ static bool parseInConfig(
 
                 if ( error == IVAS_ERR_FAILED_FILE_OPEN )
                 {
+#ifdef FIX_293_EXT_RENDERER_CLI
                     /* Failed to open with given string - most likely wasn't a file path */
+                    const CmdLnParser_Option *listOption = findOptionById( CmdLnOptionId_listFormats );
+                    fprintf( stderr, "Unsupported input format: %s. To list valid formats, use option --%s.\n", inFormatStr, listOption->match );
+#else
                     fprintf( stderr, "Unsupported input format: %s\n", inFormatStr );
+#endif
                     return false;
                 }
                 if ( error != IVAS_ERR_OK )
@@ -1144,10 +1165,20 @@ static bool parseInConfig(
             }
             break;
         default:
+#ifdef FIX_293_EXT_RENDERER_CLI
+        {
+            /* Default case covers formats that are defined in the IVAS_REND_AudioConfig enum,
+             * but cannot be used at input, e.g. BINAURAL */
+            const CmdLnParser_Option *listOption = findOptionById( CmdLnOptionId_listFormats );
+            fprintf( stderr, "Unsupported input format: %s. To list valid formats, use option --%s.\n", inFormatStr, listOption->match );
+            return false;
+        }
+#else
             /* Default case covers formats that are defined in the IVAS_REND_AudioConfig enum,
              * but cannot be used at input, e.g. BINAURAL */
             fprintf( stderr, "Unsupported input format: %s\n", inFormatStr );
             return false;
+#endif
     }
 
     return true;
@@ -1285,7 +1316,20 @@ static IVAS_REND_AudioConfig parseAudioConfig(
     }
     if ( strncmp( charBuf, "ISM", 3 ) == 0 )
     {
+#ifdef FIX_293_EXT_RENDERER_CLI
+        /* Accept input config as ISM only if the 4th character is a number from 1 to 4.
+         * Otherwise, do nothing. Unknown audio config will be returned. */
+        switch ( charBuf[3] )
+        {
+            case '1':
+            case '2':
+            case '3':
+            case '4':
+                return IVAS_REND_AUDIO_CONFIG_OBJECT;
+        }
+#else
         return IVAS_REND_AUDIO_CONFIG_OBJECT;
+#endif
     }
     if ( strncmp( charBuf, "MASA", 4 ) == 0 )
     {
@@ -1313,6 +1357,7 @@ static IVAS_REND_AudioConfig parseAudioConfig(
     return IVAS_REND_AUDIO_CONFIG_UNKNOWN;
 }
 
+#ifndef FIX_293_EXT_RENDERER_CLI
 static const CmdLnParser_Option *findOptionById(
     const int32_t id )
 {
@@ -1326,6 +1371,7 @@ static const CmdLnParser_Option *findOptionById(
 
     return NULL;
 }
+#endif
 
 static bool checkRequiredArgs(
     CmdlnArgs args )
@@ -1619,6 +1665,24 @@ void IsmPositionProvider_getNextFrame(
 
     for ( objIdx = 0; objIdx < positionProvider->numObjects; ++objIdx )
     {
+#ifdef FIX_293_EXT_RENDERER_CLI
+        /* If ISM metadata reader is open, read from metadata file */
+        if ( positionProvider->ismReaders[objIdx] != NULL )
+        {
+            getMetadataFromFileReader( positionProvider->ismReaders[objIdx], objectMetadataBuffer, objIdx );
+        }
+        /* Otherwise, if positions were provided in a scene description file, use them */
+        else if ( positionProvider->positions[objIdx] != NULL )
+        {
+            readFromShorthandMetadata( positionProvider, objectMetadataBuffer, objIdx );
+        }
+        /* Otherwise fall back to default position */
+        else
+        {
+            objectMetadataBuffer->positions[objIdx].azimuth = 0.0f;
+            objectMetadataBuffer->positions[objIdx].elevation = 0.0f;
+        }
+#else
         if ( positionProvider->ismReaders[objIdx] != NULL )
         {
             getMetadataFromFileReader( positionProvider->ismReaders[objIdx], objectMetadataBuffer, objIdx );
@@ -1627,6 +1691,7 @@ void IsmPositionProvider_getNextFrame(
         {
             readFromShorthandMetadata( positionProvider, objectMetadataBuffer, objIdx );
         }
+#endif
 
         /* Wrap azimuth to lie within (-180, 180] range */
         while ( objectMetadataBuffer->positions[objIdx].azimuth < 0.0f )
@@ -2014,7 +2079,11 @@ static void parseMasa(
     if ( strncmp( line, "MASA", 4 ) != 0 )
     {
         char numTcs = *line;
+#ifdef FIX_293_EXT_RENDERER_CLI
+        snprintf( line, 6 /* write at most 6 characters: MASAx + null termination */, "MASA%c", numTcs );
+#else
         sprintf( line, "MASA%c", numTcs );
+#endif
     }
 
     inConfig->masaBuses[idx].audioConfig = parseAudioConfig( line );
diff --git a/lib_com/options.h b/lib_com/options.h
index 09e29ce40bc35e30d7acb2d761a74a835bbe962f..b974000782006a643ef24a5efd5322c2dfad3027 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -152,6 +152,7 @@
 #define ENV_STAB_FIX                                    /* Contribution 23: HQ envelope stability memory fix */
 #define STABILIZE_GIPD                                  /* FhG: Contribution 22: gIPD stabilization */
 #define FIX_292_VBAP_CALLOC_REMOVAL                     /* Nokia: Fixes issue 292 by removing the remnant callocs */
+#define FIX_293_EXT_RENDERER_CLI                        /* FhG: Fix bugs in external renderer CLI */
 
 /* ################## End DEVELOPMENT switches ######################### */
 /* clang-format on */
diff --git a/lib_rend/lib_rend.c b/lib_rend/lib_rend.c
index 028b0f62740ece10b78b6dd79e2d07bd8746f1c6..5e59d8586129bb45d2e0c4d6a41a2f95e448b4f1 100644
--- a/lib_rend/lib_rend.c
+++ b/lib_rend/lib_rend.c
@@ -2563,7 +2563,11 @@ static IVAS_REND_InputId makeInputId(
     /* Put config type in second byte (from LSB), put index + 1 in first byte
      *
      * Index is incremented here so that a valid ID can never be 0. */
+#ifdef FIX_293_EXT_RENDERER_CLI
+    return (IVAS_REND_InputId) ( ( ( (uint32_t) getAudioConfigType( config ) ) << 8 ) | ( inputIndex + 1 ) );
+#else
     return (IVAS_REND_InputId) ( ( getAudioConfigType( config ) << 8 ) | ( inputIndex + 1 ) );
+#endif
 }
 
 static ivas_error getInputById(
diff --git a/lib_util/ism_file_writer.c b/lib_util/ism_file_writer.c
index ac90e7b1ebcb0f43275df3b725f21a53df88ebe4..e0a910d5db5f39ede867a54b70c9779bdb38b1ff 100644
--- a/lib_util/ism_file_writer.c
+++ b/lib_util/ism_file_writer.c
@@ -64,7 +64,11 @@ ivas_error IsmFileWriter_open(
     FILE *file;
 
     strncpy( metadata_filename_loc, filePathWav, sizeof( metadata_filename_loc ) - 1 );
+#ifdef FIX_293_EXT_RENDERER_CLI
+    snprintf( ext_meta, sizeof( ext_meta ), ".%d.csv", obj_num );
+#else
     sprintf( ext_meta, ".%d.csv", obj_num );
+#endif
     const int32_t maxNumCharactersToAppend = (int32_t) sizeof( metadata_filename_loc ) - strlen( metadata_filename_loc ) - 1;
     strncat( metadata_filename_loc, ext_meta, maxNumCharactersToAppend );
 
@@ -116,7 +120,11 @@ ivas_error IsmFileWriter_writeFrame(
     file = ismWriter->file;
 
     /* IVAS_fmToDo: work in progress; currently position_azimuth, position_elevation, position_radius, spread, gain_factor */
+#ifdef FIX_293_EXT_RENDERER_CLI
+    snprintf( char_buff, sizeof( char_buff ), "%+07.2f,%+06.2f,%05.2f,%06.2f,%04.2f\n", ismMetadata.azimuth, ismMetadata.elevation, ismMetadata.radius, ismMetadata.spread, ismMetadata.gainFactor );
+#else
     sprintf( char_buff, "%+07.2f,%+06.2f,%05.2f,%06.2f,%04.2f\n", ismMetadata.azimuth, ismMetadata.elevation, ismMetadata.radius, ismMetadata.spread, ismMetadata.gainFactor );
+#endif
 
     if ( file )
     {
diff --git a/lib_util/masa_file_writer.c b/lib_util/masa_file_writer.c
index e8f9a09c68d812dfa9f3f4059932c1d4046cb90b..3cfb25b494b62285cf33c5fea17a21efa6e12e54 100644
--- a/lib_util/masa_file_writer.c
+++ b/lib_util/masa_file_writer.c
@@ -66,7 +66,11 @@ static void getExtMasaMetadataFileName(
     /* sizeof( ext_meta ) accounts for terminating NULL, don't subtract extra 1 */
     const int32_t maxNameLenWithoutExt = sizeof( metadata_filename[0] ) - sizeof( ext_meta );
     strncpy( metadata_filename[0], outputWavFilename, maxNameLenWithoutExt );
+#ifdef FIX_293_EXT_RENDERER_CLI
+    snprintf( ext_meta, sizeof( ext_meta ), ".met" );
+#else
     sprintf( ext_meta, ".met" );
+#endif
 
     /* strlen( metadata_filename[0] ) doesn't account for terminating NULL, subtract extra 1 */
     const int32_t maxNumCharactersToAppend = (int32_t) ( sizeof( metadata_filename[0] ) - strlen( metadata_filename[0] ) - 1 );