UnicodeDecodeError when reading registrymodifications.xcu

[russ-p]

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/mugshot/MugshotWindow.py", line 364, in on_apply_button_clicked
    if self.get_libreoffice_details_updated():
  File "/usr/lib/python3/dist-packages/mugshot/MugshotWindow.py", line 640, in get_libreoffice_details_updated
    data = self.get_libreoffice_data()
  File "/usr/lib/python3/dist-packages/mugshot/MugshotWindow.py", line 798, in get_libreoffice_data
    for line in open(prefs_file):
  File "/usr/lib/python3.10/encodings/ascii.py", line 26, in decode
    return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 5925: ordinal not in range(128)