[Nexus 5 Q&A, Help & Troubleshooting] PewPewK:
I've had an odd bug that has been plaguing me for months since I got my Nexus 5. It's a bit hard to explain, but basically, transferring certain, specific mp3 files to my device will cause the metadata on that file to become "corrupted".

When I first noticed it, I just assumed it was a problem with the mp3 files - something about their encoding must be causing them to transfer oddly. I chalked it up to an odd bug, but all my attempts to solve it came up empty handed. However recently, I purchased a Galaxy Tab S 8.4 and, after transferring my music library, noticed that all of the files transferred successfully. This prompted me to investigate further, and has led me to a loss. Here's everything I've tried to nail down this strange bug...

1) It happens on every ROM installed on my Nexus 5. Stock, AOKP, Paranoid Android, L Developer Preview - all of them.

2) It happens on every kernel. Not sure if this would affect file transfers, but wanted to cover my basis.

3) It happens on every possible method of transferring the file, of which I've tried the following...

3a) adb push

3b) Different Computers

3c) Windows Drag and Drop

3d) AirDroid Transfer

3e) Downloading the file off my personal web server

4) It only affects .mp3 files, no other files transfer strangely, and no other corruption has occurred via USB transfers.

5) It affects the same .mp3 files every time. That is, if I have 2 files, a.mp3 and b.mp3, where a.mp3 transfers with the correct metadata and b.mp3 transfers with corrupted metadata, then every ROM, kernel, and method of transferring the file will result in a.mp3 transferring correctly and b.mp3 transferring incorrectly.

6) The corruption occurs with perhaps 10% of my mp3's. When it does occur, the symptoms vary. Album artwork is always lost and artist name, album name, and/or song title are seemingly randomly becoming corrupted. Corruptions mostly happen consistently between albums. That is, if one album with 10 songs have their artwork and artist information lost, then all songs on that album follow the same issue.

7) It only affects metadata. I can still listen to the song just fine - so it's a cosmetic error, but one that bugs the **** out of me since it messes up my organization.

To attempt to illustrate it, here's a photo of the metadata from Windows of the issue - the left being the mp3 on my desktop and the right being the same file immediately after being transferred to my Nexus 5. Notice how Album Title, Artist, and Song Title are all lost. The file then appears like this in all of my music players.

If I copy the file back from the Nexus to my desktop, the metadata is actually still intact. This probably means that the metadata isn't being "corrupted" per say, but I'm not sure I have a much better word to describe it. It simply seems to be in how the Nexus 5 is handling the metadata. But considering the issue doesn't exist on my Tab S, I'm not sure it's an Android error either. I thought it might be a unicode error, but it seems to happen for all files regardless of whether or not they are written in English or Japanese (much of my music collection is written in Japanese).

So there's a bug that's been driving me crazy since I bought my Nexus. I've tried every possible method of troubleshooting I could think of, now I'm wondering if anyone else out there has a clue.

Thanks!