[Andy Buchanan]

Hi all - long time reader, first time poster here!

I've been trying to find an answer to this issue all morning on the forums and other sites but it seems to be a bit different to the common bug/fix.

I have a 64GB Sandisk MicroSD card in my Samsung Galaxy A40.
It's about half full, mostly with .mp3 music files.
Today i had to get rid of the Google Play Music app (RIP) and find a different app to listen to the music stored locally. I went for VLC media player.
VLC has scanned the SD card and has found all the artists/songs as expected, I can start listening through the app fine - result!

The problem is, when I've plugged the phone into a PC via USB, the Music folder in the root of the SD shows all the sub-folders but that there are 0 actual files.
The same is true if I safely remove the SD card from the device and connect it via a card reader - Windows can see the drive is half full on the summary in explorer, but doesn't show any files.
If i navigate to the paths in the app 'My Files' on the A40 itself it also shows the folder structure but no .mp3 files - yet VLC is able to play them all fine still!

Things tried so far;
Cleared cache and data on 'External Storage' and 'Media Storage' system apps on A40'.
Cleared cache and data on VLC app and Google Play apps.
Ensured Windows view option is set to show hidden files.
Ensured 'My Files' app is set to show hidden system files.
Checked for 'nomedia' file in root of SD card and child folders.
Ensured all system updates are applied and firmware up to date.

Sorry for the long post but thought more detail is better. Maybe i've missed something simple but i don't think it's just that the card is corrupt as i'm still able to play the files through VLC.
Any help much appreciated!

[ManiacJoe]

From inside VLC, see if it will display the full path to a file, for debugging purposes.

[L0n3N1nja]

Did you download this music via Google Play? They hide the music files on an Android phone when downloaded as a means to fight piracy. If you are trying to download music you've bought and own from Google Play Music it needs to be done on a PC.

[B. Diddy]

Welcome to Android Central! When you connect your phone to the PC, make sure you swipe down the notification panel, tap the USB icon, and then make sure MTP or File Transfer is selected. Then see if the mp3 files are visible in Windows Explorer.

[Andy Buchanan]

Thanks for the responses all! Still stuck unfortunately.
@L0n3N1nja - all music files are standard MP3 files transferred onto the SD card from my PC at some point in the past, not Google Play downloads.
@B.Diddy - Can confirm that file transfer is selected when USB cable is connected.

Over the weekend i've done a master reset on the handset to solve another issue, and on reloading everything it's still the same.

I've switched to the media player app 'Musicolet' which is also able to find and play these MP3 files on the handset, but both the 'My Files' stock app, and Windows Explorer show the directories as empty still - it's incredibly frustrating!

[B. Diddy]

If you remove the card and insert it directly into your PC's reader, do the files show up normally?

Can you test another SD card, in case the current one is faulty (or possibly counterfeit)?

[Andy Buchanan]

Problem solved!
Handy tip from @ManiacJoe - re-checking the file path for several of the MP3s through the media player app.

In this case, almost all the subfolders (by artist) had been copied wholesale and dropped inside one particular artist's folder. But all the structure had been kept so whilst
SD\music\aerosmith\toys in the attic
was completely empty but the path still existed
SD\music\crossfade\aerosmith\toys in the attic
had all the files in there!

Bizarre occurrence, no idea how or why the device or an app has managed to copy everything into that folder.
I'm sure someone will say user error - but i'm not sure how i would even accomplish that and still leave the original root folders in place - drag and drop would have just copied etc...

Anyway, all back in place and mystery solved - thanks for all the tips!