AttributeError: 'EnsembleModel' object has no attribute 'incremental_states'

[lidongxing]

When I run the shell, " python sgnmt/decode.py --config_file fairseq.ini:, the errors ocurr:

sgnmt> Why is it rare to discover new marine mammal species ?
2022-02-24 15:02:31,595 INFO: Start time: 1645686151.5952792
2022-02-24 15:02:31,595 INFO: Next sentence (ID: 1): Why is it rare to discover new marine mammal species ?
2022-02-24 15:02:31,597 DEBUG: BPE segmentation: 'Why is it rare to discover new marine mammal species ?' => 'Why is it rare to discover new marine mam@@ mal species ?' (5933 18 39 7019 9 7631 75 2269 21907 6082 988 185)
2022-02-24 15:02:31,612 CRITICAL: Attribute error at sentence id 1: 'EnsembleModel' object has no attribute 'incremental_states'. This often indicates an error in the predictor configuration which could not be detected in initialisation. Stack trace: Traceback (most recent call last):
File "/home/lidongxing/anaconda3/envs/sgnmt_env/lib/python3.7/cmd.py", line 214, in onecmd
func = getattr(self, 'do_' + cmd)
AttributeError: 'SGNMTPrompt' object has no attribute 'do_Why'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/lidongxing/sgnmt/cam/sgnmt/decode_utils.py", line 905, in do_decode
hypos = [hypo for hypo in decoder.decode(src)
File "/home/lidongxing/sgnmt/cam/sgnmt/decoding/beam.py", line 186, in decode
self.initialize_predictors(src_sentence)
File "/home/lidongxing/sgnmt/cam/sgnmt/decoding/core.py", line 840, in initialize_predictors
p.initialize(src_sentence)
File "/home/lidongxing/sgnmt/cam/sgnmt/predictors/pytorch_fairseq.py", line 133, in initialize
self.model.incremental_states[model] = {}
File "/home/lidongxing/anaconda3/envs/sgnmt_env/lib/python3.7/site-packages/torch/nn/modules/module.py", line 1178, in getattr
type(self).name, name))
AttributeError: 'EnsembleModel' object has no attribute 'incremental_states'

How to sove it ? Thanks.