Don't worry, this is common with large files and I encountered it too! What I did was go through a million converters till one worked

BUT THAT'S NOT ACTUALLY NECESSARY

1. Open the file in a code editor (Notepad, Notepad++, Visual Studio Code, etc.)
2. Delete "window.YTD.tweet.part0 = "
3. Save file as a ".json" file

No, I don't know why I didn't originally do that.