Can't connect to JACK server

Hello, I am attempting to use this code. I can't get Docker to work on my VPS server (hosting service uses OpenVZ; stuck on Linux kernel 2.6.x, which is incompatible with Docker and I can't upgrade.) I attempted to replicate the environment outside of a Docker container by installing all the software, copying the files to the correct locations, and running forego start as root. This mostly works - everything starts up, and pulling up a browser with the server's IP does give me a a player progress bar. However, I'm getting JACK-related errors, and there is no sound. I'm also getting errors about not being able to create RT message buffer threads; I'm not trying to run with realtime scheduling and I can't install a realtime kernel on the server, but I didn't think this should be an issue. Supercollider does manage to start up correctly and does connect to JACK.

Here's an excerpt from the output:

jackd.1    | JACK server starting in non-realtime mode
jackd.1    | self-connect-mode is "Don't restrict self connect requests"
darkice.1  | Cannot create RT messagebuffer thread: Operation not permitted (1)
darkice.1  | Retrying messagebuffer thread without RT scheduling
darkice.1  | Messagebuffer not realtime; consider enabling RT scheduling for user
darkice.1  | no message buffer overruns
darkice.1  | `default' server already active
darkice.1  | Failed to open server

maxhawkins / sc_radio

Can't connect to JACK server #4