@ianfontinell said:

@Quente2 a quick search indicates that it is not just you: https://www.reddit.com/r/utorrent/comments/1wchfom/help_error_404

someone mentioned a temporary solution in there that requires you to delete some files every time before starting the app, so my only advice is, consider switching to a different client.

I want to second this. uTorrent Web in particular is generally regarded as a bad idea. Not only does it have issues with reporting to the tracker properly, but it also is extremely difficult to do things like upload a new torrent. As far as I'm aware, it also completely lacks the ability to create .torrent files as well.

If you're looking for the real uTorrent, this would be a better option, though we usually don't recommend using anything beyond version 2.2.1. I have a copy of this very version on my personal server here:

https://www.tech911solutions.com/docs/uTorrent-2.2.1.exe

If you're not using a Windows based PC, or if you're looking for something more modern, yet not full of bloatware, I would recommend qBitTorrent, as it works on just about any platform, and is just as straightforward as the uTorrent Classic.

I will also say that if you're running on a Mac, I would strongly discourage the use of Flox, as it does seem to work, however can cause all kinds of problems, especially with uploads and not reporting to the tracker properly.

someone mentioned a temporary solution in there that requires you to delete some files every time before starting the app, so my only advice is, consider switching to a different client.