Bad response from server: (500 [error,getplugins])

When trying to use the web interface for rTorrent I get an error message that looks like this:
[19.09.2017 06:50:56] WebUI started.
[19.09.2017 06:50:56] Bad response from server: (500 [error,getplugins])

The connection doesn't seem to establish properly. It doesn't show the torrents that are supposed to be there, it doesn't let me add new ones. The files are still present on the server because I can access them using an FTP client and I still have traffic, It's just ruTorrent that refuses to work. For what it's worth I've already tried restarting and changing it to a different client to no avail.