bs_align error

[lyd0527]

Hi,

bs3-align failed with the error message:

./bs3-align -1 bs_1.fq.pe -2 bs_2.fq.pe -g  -o WGBC -f sam -g ref.fa -d reference_genome/

     BS-Seeker3 beta

Traceback (most recent call last):
  File "bs3-align.py", line 434, in <module>
    'temp-' + options.outfilename + '-' + str(j + 1),
TypeError: cannot concatenate 'str' and 'NoneType' objects

Thank you~

Yuanda