diff --git a/lib_dec/ivas_ism_param_dec.c b/lib_dec/ivas_ism_param_dec.c
index 406a4890cfe4ad04f31d736eb14c6526d2eb1307..108d4068452309a13a8768da2a142432e974dbc7 100644
--- a/lib_dec/ivas_ism_param_dec.c
+++ b/lib_dec/ivas_ism_param_dec.c
@@ -1048,7 +1048,7 @@ ivas_error ivas_ism_dec_config(
             if ( st_ivas->ism_mode != last_ism_mode )
             {
                 /*ivas_ism_dec_reconfigure( st_ivas );*/
-                return IVAS_ERROR( IVAS_ERR_INTERNAL_FATAL, "\n\n!!! Error: ISM format switching not supported yet!!!\n\n" );
+                return IVAS_ERROR( IVAS_ERR_RECONFIGURE_NOT_SUPPORTED, "\n\n!!! Error: ISM format switching not supported yet!!!\n\n" );
             }
         }
     }
diff --git a/lib_dec/lib_dec.c b/lib_dec/lib_dec.c
index 69bd69f4fd9c6aa004953fe710611b437a4ccaf2..8f963664fb2e19519c483cd6a3fab7c4ff1aa8d4 100644
--- a/lib_dec/lib_dec.c
+++ b/lib_dec/lib_dec.c
@@ -1596,10 +1596,19 @@ const char *IVAS_DEC_GetErrorMessage(
             return "invalid format of input bitstream";
         case IVAS_ERR_INVALID_INDEX:
             return "invalid index";
+        case IVAS_ERR_INTERNAL:
+        case IVAS_ERR_INTERNAL_FATAL:
+            return "internal error";
+        case IVAS_ERR_RECONFIGURE_NOT_SUPPORTED:
+            return "reconfigure not supported";
+        case IVAS_ERR_UNEXPECTED_NULL_POINTER:
+            return "unexpected NULL pointer";            
 #ifdef DEBUGGING
         case IVAS_ERR_INVALID_FORCE_MODE:
             return "invalid force mode";
 #endif
+        case IVAS_ERR_FAILED_FILE_READ:
+            return "could not read from file";
         case IVAS_ERR_NOT_IMPLEMENTED:
             return "not implemented";
         case IVAS_ERR_UNKNOWN:
diff --git a/lib_enc/lib_enc.c b/lib_enc/lib_enc.c
index bcc0a62047739eb8a19491fe23083ceccb06e70a..c24467b228de5a84f56ab0850d69388595cb3815 100644
--- a/lib_enc/lib_enc.c
+++ b/lib_enc/lib_enc.c
@@ -1348,6 +1348,7 @@ const char *IVAS_ENC_GetErrorMessage(
         case IVAS_ERR_INDEX_OUT_OF_BOUNDS:
             return "index out of bounds";
         case IVAS_ERR_INTERNAL:
+        case IVAS_ERR_INTERNAL_FATAL:
             return "internal error";
         case IVAS_ERR_RECONFIGURE_NOT_SUPPORTED:
             return "reconfigure not supported";