IndexError: list index out of range error

I have some Question.
What’s Wrong with this problem??

command

!python OpenNMT-py/translate.py -model OpenNMT-py/data/model/model_step_1000.pt -src OpenNMT-py/data/src-val-bpe.txt -output OpenNMT-py/data/pred.txt -replace_unk -verbose -gpu 0

Error

Traceback (most recent call last):
File “OpenNMT-py/translate.py”, line 6, in
main()
File “/content/OpenNMT-py/onmt/bin/translate.py”, line 49, in main
translate(opt)
File “/content/OpenNMT-py/onmt/bin/translate.py”, line 33, in translate
attn_debug=opt.attn_debug
File “/content/OpenNMT-py/onmt/translate/translator.py”, line 353, in translate
translations = xlation_builder.from_batch(batch_data)
File “/content/OpenNMT-py/onmt/translate/translation.py”, line 95, in from_batch
for n in range(self.n_best)]
File “/content/OpenNMT-py/onmt/translate/translation.py”, line 95, in
for n in range(self.n_best)]
IndexError: list index out of range

Thanks.

Duplicate of: