"Unexpected token" for JSON files with non-UTF-8 encoding

Some songs can’t be previewed and display an error:

Uncaught SyntaxError: Unexpected token � in JSON at position 0
    at JSON.parse (<anonymous>)
    at ZipLoader.extractAsJSON (build.js:274)
    at Object.keys.forEach.filename (build.js:96)
    at Array.forEach (<anonymous>)
    at ZipLoader.loader.on (build.js:96)
    at ZipLoader.dispatch (build.js:274)
    at XMLHttpRequest.xhr.onload (build.js:274)

This is due to non-UTF-8 encoding in .json files (checked with Notepad++).

Examples of UCS-2 LE BOM in info.json:

1. https://supermedium.com/beatsaver-viewer/?id=5239-4638
2. https://supermedium.com/beatsaver-viewer/?id=10606-11164
3. https://supermedium.com/beatsaver-viewer/?id=10880-11495

[ngokevin]

We can’t live without kpop!

[ngokevin]

Thanks, I had some code to normalize it, I’ll add it later.