Error when running m17_forward.py

[Radiomix2000]

When I run m17_forward.py (generated from m17_forward.grc) I see the next error:

Executing: /usr/bin/python3 -u /home/armin/OOT/gr-m17/examples/m17_forward.py Traceback (most recent call last): File "/home/armin/OOT/gr-m17/examples/m17_forward.py", line 174, in main() File "/home/armin/OOT/gr-m17/examples/m17_forward.py", line 152, in main tb = top_block_cls() File "/home/armin/OOT/gr-m17/examples/m17_forward.py", line 87, in init self.m17_m17_lich_gen_0 = m17.m17_lich_gen('ABCDEFG', 'HIJKLMN', 4, 0) File "/usr/local/lib/python3.8/dist-packages/m17/m17_lich_gen.py", line 41, in init self.lich_array = numpy.array(self.lich.asList(), dtype=numpy.int8) File "/usr/local/lib/python3.8/dist-packages/m17/m17_lich.py", line 112, in asList return list(self._encode()) File "/usr/local/lib/python3.8/dist-packages/m17/m17_lich.py", line 100, in _encode _encode_base40(self.dst) + TypeError: can't concat int to bytearray

Any suggestions, what's wrong?