This is an unknown extension, where the critical field (BOOLEAN) is 0.

This is not valid because the critical field has a default of FALSE, so under
DER-encoding it should be omitted.

#-----BEGIN EXTENSION-----
SEQUENCE {
  # https://davidben.net/oid
  OBJECT_IDENTIFIER { 1.2.840.113554.4.1.72585.0 }
  BOOLEAN { `00` }
  OCTET_STRING {
    SEQUENCE {}
  }
}
#-----END EXTENSION-----


-----BEGIN CERTIFICATE-----
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
-----END CERTIFICATE-----

ERROR: Failed parsing extensions

-----BEGIN ERRORS-----
RVJST1I6IEZhaWxlZCBwYXJzaW5nIGV4dGVuc2lvbnMK
-----END ERRORS-----