diff --git a/swh/indexer/metadata_dictionary/cff.py b/swh/indexer/metadata_dictionary/cff.py
--- a/swh/indexer/metadata_dictionary/cff.py
+++ b/swh/indexer/metadata_dictionary/cff.py
@@ -27,7 +27,6 @@
         try:
             content_dict = yaml.load(raw_content_string, Loader=yaml.SafeLoader)
         except yaml.scanner.ScannerError:
-            self.log.warning("Error yaml is invalid and will be skipped")
             return None
 
         if isinstance(content_dict, dict):
diff --git a/swh/indexer/metadata_dictionary/npm.py b/swh/indexer/metadata_dictionary/npm.py
--- a/swh/indexer/metadata_dictionary/npm.py
+++ b/swh/indexer/metadata_dictionary/npm.py
@@ -133,73 +133,6 @@
             author[SCHEMA_URI + "url"] = {"@id": url}
         return {"@list": [author]}
 
-    def normalize_description(self, description):
-        r"""Try to re-decode ``description`` as UTF-16, as this is a somewhat common
-        mistake that causes issues in the database because of null bytes in JSON.
-
-        >>> NpmMapping().normalize_description("foo bar")
-        'foo bar'
-        >>> NpmMapping().normalize_description(
-        ...     "\ufffd\ufffd#\x00 \x00f\x00o\x00o\x00 \x00b\x00a\x00r\x00\r\x00 \x00"
-        ... )
-        'foo bar'
-        >>> NpmMapping().normalize_description(
-        ...     "\ufffd\ufffd\x00#\x00 \x00f\x00o\x00o\x00 \x00b\x00a\x00r\x00\r\x00 "
-        ... )
-        'foo bar'
-        >>> NpmMapping().normalize_description(
-        ...     # invalid UTF-16 and meaningless UTF-8:
-        ...     "\ufffd\ufffd\x00#\x00\x00\x00 \x00\x00\x00\x00f\x00\x00\x00\x00"
-        ... ) is None
-        True
-        >>> NpmMapping().normalize_description(
-        ...     # ditto (ut looks like little-endian at first)
-        ...     "\ufffd\ufffd#\x00\x00\x00 \x00\x00\x00\x00f\x00\x00\x00\x00\x00"
-        ... ) is None
-        True
-        >>> NpmMapping().normalize_description(None) is None
-        True
-        """
-        if description is None:
-            return None
-        # XXX: if this function ever need to support more cases, consider
-        # switching to https://pypi.org/project/ftfy/ instead of adding more hacks
-        if description.startswith("\ufffd\ufffd") and "\x00" in description:
-            # 2 unicode replacement characters followed by '# ' encoded as UTF-16
-            # is a common mistake, which indicates a README.md was saved as UTF-16,
-            # and some NPM tool opened it as UTF-8 and used the first line as
-            # description.
-
-            description_bytes = description.encode()
-
-            # Strip the the two unicode replacement characters
-            assert description_bytes.startswith(b"\xef\xbf\xbd\xef\xbf\xbd")
-            description_bytes = description_bytes[6:]
-
-            # If the following attempts fail to recover the description, discard it
-            # entirely because the current indexer storage backend (postgresql) cannot
-            # store zero bytes in JSON columns.
-            description = None
-
-            if not description_bytes.startswith(b"\x00"):
-                # try UTF-16 little-endian (the most common) first
-                try:
-                    description = description_bytes.decode("utf-16le")
-                except UnicodeDecodeError:
-                    pass
-            if description is None:
-                # if it fails, try UTF-16 big-endian
-                try:
-                    description = description_bytes.decode("utf-16be")
-                except UnicodeDecodeError:
-                    pass
-
-            if description:
-                if description.startswith("# "):
-                    description = description[2:]
-                return description.rstrip()
-        return description
-
     def normalize_license(self, s):
         """https://docs.npmjs.com/files/package.json#license
 
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -101,7 +101,7 @@
     given-names: Stephan
     orcid: https://orcid.org/0000-0003-4925-7248
 cff-version: "1.0.3"
-date-released: 2019-11-12
+date-released: "2019-11-12"
 doi: 10.5281/zenodo.1162057
 keywords:
   - "citation"
@@ -159,6 +159,31 @@
         # then
         assert expected == result
 
+    def test_compute_metadata_cff_invalid_yaml(self):
+        """
+        test.yaml translation for invalid yaml file
+        """
+        # given
+        content = """cff-version: 1.0.3
+message: To cite the SigMF specification, please include the following:
+authors:
+  - name: The GNU Radio Foundation, Inc.
+title: The Signal Metadata Format (SigMF)
+version: 0.0.1
+doi: 10.5281/zenodo.1418396
+date-released: 2018-07-18
+license: CC-BY-SA-4.0
+url: https://sigmf.org
+        """.encode(
+            "utf-8"
+        )
+
+        expected = None
+
+        result = self.cff_mapping.translate(content)
+        # then
+        assert expected == result
+
     def test_compute_metadata_npm(self):
         """
         testing only computation of metadata with hard_mapping_npm