Error playing media on cached media

Issue description:

I have a subsonic server registered on the app. I am able to play and cache music. When on mobile data, even with a good connection with the server, when I try to play a cached álbum, I get the error “Error playing media, ensure that your player supports it”.
Not sure what could be causing this.

Alongside the post, I’m attaching a log file and a screen recording.

Logs: (11.6 KB)


Thanks in advance!

The logs shows that something intercept the data on the loopback interface and cause the issue.

Do you use some VPN or something else on that device?

Offline cached media is served via an internal server but your device send the data to something that then fails with error 504.

Maybe there’s configuration in your network tools to not proxy

I do use OpenVPN but I have it disabled most of the time, including on the demo

Well I don’t know what you use that triggers that the logs don’t tell.

But the Symfonium webserver does not return error 504, and the consumer does not return error 504 either.

So the error : Response code: 504 is returned by something else and it’s the cause of the issue. Symfonium can’t access itself on the loopback interface.

Uninstalled OpenVPN but nothing changed. Other than that this is a clean installed ROM. I took the opportunity to share this issue now since it remained after a clean install of a new ROM. Thought it was something messed up with the old one.

Playing a non-chached album works.

I can’t tell you much more that what I just explained.

Something on your device intercept the data on the loopback interface and causes this.
VPN, exposed module, adblock, DNS stuff I don’t know and can’t know.

All I know is that this is something outside Symfonium and that it’s normally not possible.

On mobile or on Wifi Symfonium do use the loopback interface to communicate (
The fact that it’s an issue only on mobile further implies that there’s something specific in that case.

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Thanks for the help. I’ll see if I can figure out what’s causing this.
If I do, I’ll report back.

One easy test could be to try in plane mode.

Yep, playing cached music works on airplane mode.

You have your answer when in mobile mode something intercept the loopback, this is not a normal / default behavior on Android.
There’s not much I can do here

This might be something related to magisk. Disabled everything (zygisk, systemless hosts, etc) and symfonium started working properly.

Edit: maybe not. It was working because my phone connected to my local wifi (where my subsonic server is being hosted). When I changed to mobile data it stopped working again.

Unless you have enabled transcoding for download and the option prefer server version being on same Wifi as your server have nothing to do with the issue you could be connected to any wifi it would be the same.

Remember that it works in plane mode too.

For next version I’ll try to less rely on internal webserver when playing from the cache, this will make the renderer transition to remote players a little slower but not a lot, and this is not really the main use case.