COPY FROM fails when importing blob

When we try to COPY TO a table containing a blob, we get this error
COPY test.blobTable FROM '/tmp/test1.csv' WITH NULL='null' AND DELIMITER=',' AND QUOTE='"';

/opt/apache-cassandra-2.1.13.4/bin/../pylib/cqlshlib/copyutil.py:1602: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
/opt/apache-cassandra-2.1.13.4/bin/../pylib/cqlshlib/copyutil.py:1850: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
Failed to import 5 rows: ParseError - fromhex() argument 1 must be unicode, not str - given up without retries
Failed to process 5 rows; failed rows written to import_test_blobTable.err

Same COPY TO function worked fine with 2.1.9
The csv is generated by doing a COPY FROM on the same table.
Is there any work around this issue?