Key Error in sswobj.py

[MAldBio]

I am using a program (Bamsplit) that relies on ssw to run, and get the following SSW error:

File "[...]/bamsplit-master/bamsplit.py", line 266, in <module>
    main(parsed)
  File "[...]/bamsplit-master/bamsplit.py", line 235, in main
    run_bamsplit(ref, bam_in, vcf, vcf.header.samples[0], bams_out, bed_out, region)
  File "[...]Software/bamsplit-master/bamsplit.py", line 225, in run_bamsplit
    split_contig(contig, ref, bam_in, vcf, sample, bams_out, bed_out)
  File "[...]/Software/bamsplit-master/bamsplit.py", line 211, in split_contig
    last_read = split(phased_sites, ref, bam_iter, sample, bams_out, bed_out, last_read)
  File "[...]/Software/bamsplit-master/bamsplit.py", line 194, in split
    scores = calculate_alignment_scores(read.query_sequence, genotype)
  File "[...]/Software/bamsplit-master/bamsplit.py", line 159, in calculate_alignment_scores
    return [calculate_alignment_score(read, haplotype) for haplotype in genotype]
  File "[...]/Software/bamsplit-master/bamsplit.py", line 159, in <listcomp>
    return [calculate_alignment_score(read, haplotype) for haplotype in genotype]
  File "[...]/Software/bamsplit-master/bamsplit.py", line 155, in calculate_alignment_score
    alignment = aligner.align(reference=haplotype, query=read)
  File "[...]/.local/lib/python3.7/site-packages/ssw-0.3.1-py3.7-linux-x86_64.egg/ssw/sswobj.py", line 99, in align
    res = self._align(query, reference, flags, filter_score, filter_distance, mask_length)
  File "[...].local/lib/python3.7/site-packages/ssw-0.3.1-py3.7-linux-x86_64.egg/ssw/sswobj.py", line 109, in _align
    _reference = self.matrix.convert_sequence_to_ints(reference)
  File "[...]/.local/lib/python3.7/site-packages/ssw-0.3.1-py3.7-linux-x86_64.egg/ssw/sswobj.py", line 64, in convert_sequence_to_ints
    return _seq_type(*seq_generator)
  File "[...]/.local/lib/python3.7/site-packages/ssw-0.3.1-py3.7-linux-x86_64.egg/ssw/sswobj.py", line 63, in <genexpr>
    seq_generator = (self.symbol_map[symbol.upper()] for symbol in seq)
KeyError: '<'

I thought it might be a problem with "<" not being able to run through "symbol.upper()", so I attempted to manually remove all ".upper()" commands, in the sswobj.py file, but that was unable to correct the problem. Any idea on what what the issue is?