unicode error

Unhandled exception in thread started by <function run at 0x184cc08>
Traceback (most recent call last):
  File "core/main.py", line 66, in run
    out = func(input.inp, **kw)
  File "plugins/markov.py", line 73, in log
    generated = gen_message(key, channel, rcon)
  File "plugins/markov.py", line 47, in gen_message
    key = separator.join(words[1:] + [next_word])
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)