If you are having trouble with this, all you need to do is update webui core.
It's quite simple actually.
- Go to this thread in µTorrent's forum, and in the first post you'll find the download link to the last version of webui.zip.
- Close µTorrent if it is opened, and go %appdata%\uTorrent
- Remove the old webui.zip and replace with the latest version you've just downloaded. Make sure to rename it to webui.zip.
- Open up µTorrent again, and voilà.
- Now you can add magnet links though the Add from url option in µRemote.
Now, you can use those awesome magnet links