CalledProcessError: Command returned non-zero exit status 1.

[nameless0704]

With those .tsf files and .0 .1 files nice and neat, running the bleu perl program called an error:
CalledProcessError: Command 'perl C:\Users\myname\DualRL\utils\script\multi-bleu.perl C:\Users\myname\DualRL/references/yelp/reference0.1 C:\Users\myname\DualRL/references/yelp/reference1.1 C:\Users\myname\DualRL/references/yelp/reference2.1 C:\Users\myname\DualRL/references/yelp/reference3.1 < C:/Users/myname/DualRL/tmp/output/yelp_final/0_test.1.tsf' returned non-zero exit status 1.

I thought the .perl file may be some famous public program for bleu calculation but it only mentions "return" once so I'm not sure where the problem is. I'm using the original code/perl program and yelp dataset with minor changes.