GNURadio Extras error

Hello

I have a working system that used to work perfectly but now I am getting
this unknown error. Can Some body help me with it.

handler caught exception: in method
‘gr_block_gw_message_type_work_args_return_value_set’, argument 2 of
type
‘int’
Traceback (most recent call last):
File
“/usr/lib/python2.7/dist-packages/gnuradio/extras/block_gateway.py”,
line 53, in eval
try: self._callback()
File
“/usr/lib/python2.7/dist-packages/gnuradio/extras/block_gateway.py”,
line 124, in __gr_block_handle
) for i in self.__out_indexes],
TypeError: in method
‘gr_block_gw_message_type_work_args_return_value_set’,
argument 2 of type ‘int’
thread[thread-per-block[6]: <gr_block mod_pkts2 (32)>]: caught
unrecognized
exception

Regards

Abid