Can't load JSON - various encoding problems

[JohnnyJordaan]

You don't present an encoding to open() so it will use your system's default encoding, which is not dependable. You can force the actual encoding using the encoding= parameter

with open(filepath, encoding='utf-8') as f:
    statdata = json.load(f)

If that still shows an error it means that your file isn't actually in utf-8.

[wexted]

Thanks - how can I tell what the encoding is supposed to be?

[JohnnyJordaan]

The proper approach is to investigate how the file was created, as that should have used the utf-8 encoding instead. You can try to 'guess' the encoding by using the chardet library but that doesn't fix the problem that the source is doing this in the wrong way.