SOLVED: Cannot connect over LAN

[MisterGriimm]

I've been using Jellyfin for around 3 years now with no significant issues.
Last night my wife was watching a show on our Android TV with the Jellyfin App and it just stopped midway through.

I'm running Server Version 10.10.3 on a Windows 10 PC
I have Starlink Internet (no ethernet) - I have run it with the ethernet adapter and a 3rd party router through the starlink in the past.
I typically update the server approximately 1-2 weeks after I get the notice from the web client. Never been an issue.

What stumps me the most is that I've been running this pretty consistently, and it's never had networking issues.
I can't think of a single thing that would have "triggered" this to not work now.
I've switched ISP's like 3 times and it's always plug'n'play.

I assumed that maybe it was something to do with ports or the firewall, so I went in and removed and re-added the 8096 TCP rule to allow all, as well as the program specific rule.

All network settings within Jellyfin are default. I had remote connections enabled before (assuming it's not gonna be a factor as I'm just trying to stream over LAN).

Basically scrubbed through reddit and the forums of older posts and I'm at my wits end.

I removed the 3 or 4 plugins I had (aesthetic changes) and reinstalled from scratch... still no dice.

Then I figure, maybe I'll try with Tailscale and see how that works.
No issues. Can use my tailscale VPN and connect from my phone instantly. But the second I try my local IP address with the port it times out on all devices other than the server device itself.

Any suggestion is appreciated, I'm super confused and have no clue what the problem could be.

[bitmap]

Static IP set for the server? Are you able to access the web client from the PC that Jellyfin is running on?

[MisterGriimm]

Static IP set for the server? Are you able to access the web client from the PC that Jellyfin is running on?

To my knowledge it's not a static IP set. Default starlink stuff won't allow me to do that (AFAIK) I can use the IP address or localhost on the server PC itself and it works just fine.
I did scroll through the logs and saw this - Not a networking guy, so not 100% certain how to decipher what's wrong:

[2025-03-26 14:43:49.655 -08:00] [ERR] [1] Main: Kestrel failed to start! This is most likely due to an invalid address or port bind - correct your bind configuration in network.xml and try again
[2025-03-26 14:43:49.657 -08:00] [FTL] [1] Main: Error while starting server
System.IO.IOException: Failed to bind to address http://0.0.0.0:8096: address already in use.
---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted.
---> System.Net.Sockets.SocketException (1004: Only one usage of each socket address (protocol/network address/port) is normally permitted.
  at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, Boolean disconnectOnFailure, String callerName)
  at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
  at System.Net.Sockets.Socket.Bind(EndPoint localEP)
  at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportOptions.CreateDefaultBoundListenSocket(EndPoint endpoint)
  at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
  --- End of inner exception stack trace ---
  at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
  at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.TransportManager.BindAsync(EndPoint endPoint, ConnectionDelegate connectionDelegate, EndpointConfig endpointConfig, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.<>c__DisplayClass28_01.<<StartAsync>g__OnBind|0>d.MoveNext()
--- End of stack trace from previous location ---
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context, CancellationToken cancellationToken)
  --- End of inner exception stack trace ---
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.ListenOptions.BindAsync(AddressBindContext context, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.EndpointsStrategy.BindAsync(AddressBindContext context, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(ListenOptions[] listenOptions, AddressBindContext context, Func2 useHttps, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.BindAsync(CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.StartAsync[TContext](IHttpApplication1 application, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Hosting.GenericWebHostService.StartAsync(CancellationToken cancellationToken)
  at Microsoft.Extensions.Hosting.Internal.Host.<StartAsync>b__15_1(IHostedService service, CancellationToken token)
  at Microsoft.Extensions.Hosting.Internal.Host.ForeachService[T](IEnumerable1 services, CancellationToken token, Boolean concurrent, Boolean abortOnFirstException, List1 exceptions, Func3 operation)
  at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(CancellationToken cancellationToken)
  at Jellyfin.Server.Program.StartServer(IServerApplicationPaths appPaths, StartupOptions options, IConfiguration startupConfig)

[TheDreadPirate]

Open Task Manager and double check that you don't have a zombie jellyfin process running. Another process is bound to port 8096 and jellyfin can't start due to that.

[MisterGriimm]

Open Task Manager and double check that you don't have a zombie jellyfin process running.  Another process is bound to port 8096 and jellyfin can't start due to that.

I thought something similar - no zombie instance.
Did some digging with ChatGPT, turns out I can't ping the device from my iPhone or other devices on the network... so I guess I'll restart everything on the network level AGAIN. Maybe I wasn't thorough enough the first time. I really don't wanna take it to zero... but with Starlink's base setup I have no clue if there's a way to fix it without doing so. Might just go back to my external router. ugh. Will post update tomorrow or the day after.

[MisterGriimm]

Well.. I don't know what I did wrong the first time I restarted my router, but I guess it works now... so bizarre.

[TheDreadPirate]

Do you have Automatic port mapping enabled in Jellyfin?