Issues syncing to Android devices ("device is unreachable")

[jack94]

Hi all, looking for some troubleshooting help with the syncing feature, specifically USB syncing to Android devices. The current device is a Fiio M21; I'm syncing to the SD card in it rather than to the built-in memory, if that matters. I'm running MusicBee Portable version 3.5.

The issue I get is that the sync progresses without any issues for a while, and then suddenly stalls and gives me the same error message for all the remaining files. For a while it was importing ~2,000 files successfully and then showing errors. Right now it only gets through around 300 and then shows errors. A small part of the error log:

10/06/2025 19:41:25 - Copy D:\MB Portable\MusicBee\Library\Music\Alan Sparhawk\With Trampled by Turtles\08 Don’t Take Your Light.flac to FiiO M21\M21 Micro SD\Music\Alan Sparhawk\With Trampled by Turtles\08 - Don’t Take Your Light.mp3
10/06/2025 19:41:25 - The device is unreachable. (Exception from HRESULT: 0x80070141)
10/06/2025 19:41:26 - Copy D:\MB Portable\MusicBee\Library\Music\Aphex Twin\Loose Tracks\1-01 Pac-Man.flac to FiiO M21\M21 Micro SD\Music\Aphex Twin\Loose Tracks\1-01 - Pac-Man.mp3
10/06/2025 19:41:26 - The device is unreachable. (Exception from HRESULT: 0x80070141)

On other occasions the error has been a bit different:

09/06/2025 20:30:08 - Copy D:\MB Portable\MusicBee\Library\Music\Bruce Springsteen\We Shall Overcome  The Seeger Sessions\1-01 Old Dan Tucker.mp3 to FiiO M21\M21 Micro SD\Music\Bruce Springsteen\We Shall Overcome  The Seeger Sessions\1-01 - Old Dan Tucker.mp3
09/06/2025 20:30:08 - The requested resource is in use. (Exception from HRESULT: 0x800700AA)
09/06/2025 20:30:08 - Copy D:\MB Portable\MusicBee\Library\Music\Bruce Springsteen\We Shall Overcome  The Seeger Sessions\1-02 Jesse James (Just Ask).mp3 to FiiO M21\M21 Micro SD\Music\Bruce Springsteen\We Shall Overcome  The Seeger Sessions\1-02 - Jesse James (Just Ask).mp3
09/06/2025 20:30:08 - The requested resource is in use. (Exception from HRESULT: 0x800700AA)

The same pattern repeats, though: syncing successfully for a while and then displaying errors for the rest of the files. You can see my syncing settings here:



Other things I can think of that might be relevant: It takes a long time after connecting the device—I'd say up to half an hour—for the sync to actually start (or even for the preview to appear); but I think this may just be due to the very large number of files involved. In any case, I have to wait through this again for each new attempted sync.

Also, I have made sure the Android device isn't going to sleep during the syncing process, so that shouldn't be the problem.

I've had similar issues with syncing over the years, the same kinds of issues with several different (Android) devices; I wonder if Android, or Windows, just automatically blocks the connection after a certain length of time, and if there's any way to stop it doing so? If the sync works for some people, I suppose there must be. This issue seems to have come and gone somewhat unpredictably over time for me, and I'm never sure if I've done anything to fix it or it just fixes itself randomly. In this instance, anyway, it seems persistent.

I'm currently trying to sync a very large library to the device, which becomes pretty much infeasible when the sync habitually stalls after a few hundred tracks. If it's, say, 1,000 files I want to sync, it still bugs out but I can get it done in a few attempts. If it's 130,000, it's just not doable. So if anyone has experienced a similar issue or has ideas on where to look for solutions, I would really appreciate it! I'm aware that similar issues have been raised on the forum before, but I haven't been able to find any threads with a solution to the problem.

And please let me know if there's other info that would be useful for identifying the problem.

[phred]

The first thing I'd suggest doing is updating MB to the latest version 3.6. Since you're using Portable, download the latest patch version from my signature below and see if that helps. What you're currently using could be almost two years old.

I also noticed, at least in your first screenshot, that the path and filename is extremely long. I don't know how Filo handles long paths, but Windows has a maximum length and that may be coming into play as you attempt to transfer the files.

[jack94]

The first thing I'd suggest doing is updating MB to the latest version 3.6. Since you're using Portable, download the latest patch version from my signature below and see if that helps. What you're currently using could be almost two years old.

I also noticed, at least in your first screenshot, that the path and filename is extremely long. I don't know how Filo handles long paths, but Windows has a maximum length and that may be coming into play as you attempt to transfer the files.

Thanks, I'll try the patch and see if that helps.

I haven't noticed any pattern with long file paths specifically triggering the errors, it seems to just start happening after a length of time that's consistent enough to suggest to me that isn't the issue. But still, I can try to shorten both the Windows file paths and what they're being mapped to on the device, and see if it helps.

I'll give both of those a go and report back whether anything changes!

[phred]

Re-reading your error log snips, I suggest doing a dedicated MB Google search (see my sig below and bookmark it for future reference) and search for "Exception from HRESULT". There's four pages of hits and I'm not looking at any of them. But you might find something helpful there.

[jack94]

So just to update, the patch and the shortened file paths didn't seem to make any difference, errors continued just as before unfortunately.

Now trying a different workaround of using a USB memory card reader to sync directly to the SD card. So far, at least, this has got through a far higher number of files than the sync usually would, with no errors. So, still not knowing exactly what causes the issue, all signs point to it being Android's fault.

Hopefully this is useful info if anyone else runs into the same issue.