kmer_prism crashes on some tag count files

[afmcc]

Traceback (most recent call last):
File "/dataset/hiseq/active/bin/DECONVQC/kmer_prism.py", line 469, in
main()
File "/dataset/hiseq/active/bin/DECONVQC/kmer_prism.py", line 461, in main
distributions = build_kmer_distributions(options)
File "/dataset/hiseq/active/bin/DECONVQC/kmer_prism.py", line 289, in build_kmer_distributions
options["kmer_size"], options["input_driver_config"]))
File "/dataset/hiseq/active/bin/DECONVQC/kmer_prism.py", line 251, in build_kmer_distribution
distdata = build(distob, use="singlethread")
File "/bifo/active/hiseq/bin/DECONVQC/data_prism.py", line 862, in build
results.append(build_part(arg))
File "/bifo/active/hiseq/bin/DECONVQC/data_prism.py", line 836, in build_part
return distob.get_partial_distribution(slice_number)
File "/bifo/active/hiseq/bin/DECONVQC/data_prism.py", line 139, in get_partial_distribution
raw_values = self.get_raw_values_stream()
File "/bifo/active/hiseq/bin/DECONVQC/data_prism.py", line 120, in get_raw_values_stream
file_streams = [self.file_to_stream_func(filename, *self.file_to_stream_func_xargs) for filename in self.input_filenames]
File "/dataset/hiseq/active/bin/DECONVQC/kmer_prism.py", line 145, in tag_count_from_tag_count_file
while( common_prefix_length < min(len(sorted_tuples[0]), len(sorted_tuples[-1])) ):
IndexError: list index out of range

[afmcc]

(relates to some odd data under 180607_D00390_0368_BCCJJVANXX/SQ0705)