I was able to reproduce this bug with many different codes, here is one example.
b = bchlib.BCH(2, m=5, swap_bits=True)
w = b'\x00\x00\xa0' # random word
d = b'\xe0\x03' # the string you get from encoding
b.decode(data=w, recv_ecc=d)
^^^^^^^^
ValueError: invalid parameters
this also happens for swap_bits = False.
using python 3.10.8. version 2.1.3 of library.
For some codes, such as t=10,m=7 this doesn't happen