worker is errors

[hus18]

Traceback (most recent call last):
File "./worker.py", line 419, in
main()
File "./worker.py", line 409, in main
decoder_pipeline = DecoderPipeline2(conf)
File "/opt/kaldi-gstreamer-server/kaldigstserver/decoder2.py", line 25, in init
self.create_pipeline(conf)
File "/opt/kaldi-gstreamer-server/kaldigstserver/decoder2.py", line 55, in create_pipeline
self.asr.set_property("use-threaded-decoder", conf["decoder"]["use-threaded-decoder"])
AttributeError: 'NoneType' object has no attribute 'set_property'