Android files suddenly don't appear on my PC

[Android Central Question]

My Windows 10 pc no longer displays the files on my android phone (but the folders on the phone are displayed normally).

I replaced the SD card in my phone, for which I had to disable the fusion/ adopted storage option. The switch worked fine, and the new SD card is mounted.

Now when I connect the phone to the pc, the device and the SD card show up normally in Windows Explorer, and so do all the folders (e.g. Android, data...) on both the phone and the SD card.

However, none of the android files (apps, etc.) on either the phone or SD card are displayed. The apps are definitely still there on the phone, and they are working fine; the pc also shows correctly the total amount of data stored in the phone's internal memory. I can also see and open the media files in the folders on my SD card on my pc

I've already tried re-installing the drivers and clearing the data + cache for both the external storage and the media storage on my phone. USB debugging is enabled, and the phone is connected in MTP mode. I've also tried connecting the phone to a differerent computer -- same problem.

FWIW, I'm running fairly stock Lollipop (5.1).

Does anyone have any idea what the problem is, and how I can fix it?

 

[Rukbat]

The card is installed as portable (external)? (If it's installed as adaptable [internal], the card is there physically, but not logically - logically it's just part of "storage").

Either of 2 methods to diagnose the problem:

Run a file manager and see what files are where. Or remove the card from the phone and connect it to the PC (you'll need the full-size adapter that should have come with it and you'll probably need a USB SD card adapter).

Then register an account here and post the results i this thread, so you don't have to repeat everything in a new thread. (Guests can't post to existing threads.)

 

[Questor11]

Thanks for your answer, Rukbat. I didn't realize that guests couldn't post in existing threads, but now I've signed up.
So the SD card is installed as external at the moment (I found that using it as "adoptable" storage clogged up my internal storage just as much as if I hadn't merged the two). However, the problem is not with the SD card per se; since the switch, I can't display the android-format files that are present on the phone's internal storage either.
I suspect that the problem is with the indexing on the phone itself, since the phone's native file manager shows most of the folders (even those in the internal memory) as "empty". This seems to apply to all the program files (apps), even thought the files are there and working.
The exception are the data files (pictures and music), which DO appear in both the native file manager and on the pc -- but these files are in jpg or mp3 format, and therefore not android-specific -- maybe that's why they show up, and the other files/ apps don't? Could it be a problem with indexing files that have android-specific extensions?
Thanks for any advice you may have.

 

[Rukbat]

I suspect that the problem is with the indexing on the phone itself, since the phone's native file manager shows most of the folders (even those in the internal memory) as "empty".

Bingo! There's your answer. Expecially:

This seems to apply to all the program files (apps), even thought the files are there and working.
The exception are the data files (pictures and music), which DO appear in both the native file manager and on the pc

Android runs on Linux. If you (the user we signed in as when we're running Android) aren't superuser (meaning a rooted phone), you aren't the app the folder belongs to, or it isn't readable by the user "everyone", all you see is an empty folder.

That's normal in any implementation of *nix - Unix, Linux, MacOS.

Could it be a problem with indexing files that have android-specific extensions?

Not extensions - permissions. You can't see ogg, mp3, jpg or png files in an app's folder either.

 

[Questor11]

Thanks again, Rukbat. So then I have two questions:

1) why did this happen just now, after I switched out the SD card, when it worked fine before and I could see all the files in the file manager and on my pc? Did I accidentally delete some stock permissions when I disabled the adoptable storage?

2) What do I do now? Am I looking at a factory reset?

 

[Rukbat]

1) No idea. It shouldn't have.

2) The only way to see those files is to be rooted.

 

[Questor11]

Thanks, but my phone wasn't rooted before the SD card switch, and yet I used to see all the files that are now not being displayed.

I think there's a problem with the indexing on the phone itself, I just can't figure out what has changed.

 

[Rukbat]

Normally, if you look in a folder like /data, you'll see nothing in there. if the phone is rooted, you'll see other folders in /data.

Why you were able to see those files and folders before is one of those "shouldn't be" things (unless the phone was rooted without your knowledge).

As for "indexing", the directory structure isn't indexed, it's not a database. If the phone can run an app, it's listed, or the phone wouldn't be able to find it to run it. But the launcher, file managers, and apps like that, have permissions to those directories. The user (you and I) doesn't - unless the phone is rooted, in which case, when we turn the phone on, we're logging in as superuser.

 

[Questor11]

I should add -- when I download a new apk onto the internal storage, it appears. But the old apks and other files don't show up.

 

[Rukbat]

The apk is just a file, it's not the app. It still has to be installed. Other apps? You may have just installed them from Play, so there won't be any apk files left.

 

[Questor11]

Nope -- I downloaded and installed numerous files from third-party sites prior to the SD card switch, and up until the switch, they were all still displayed when using the file manager or via USB MTP on my pc to look at the internal memory.

Now when I put a new apk on the phone, I can see it AND install the new app, but that app can't connect to the related data files that are stored on the SD card in the Android/obb folder, so it doesn't run properly.

It seemed like a simple plan:
1) Back up the SD card on my pc
2) Disable fusion storage
3) replace the old SD card with the new one
4) reload the backed-up data from the pc onto the new SD card in the phone

All those steps seemed to go fine, so I don't know what went wrong. Maybe disabling the adoptable "fusion" storage wreaked this havoc on my phone (e.g., by preventing apps on the internal memory from locating their data on the SD card)?

I was trying to declutter my internal storage, which is nearly full, by deleting unneeded apps and their apks, but if I can't find them any more, I obviously can't delete them.

Anyway, I'm starting to fear that I may have to do a factory reset and simply start again from scratch. Thanks for all your advice.

 

[methodman89]

Install Data Size Explorer from the playstore and see what is using memory.

 

[Rukbat]

"Fusion storage"? As in - you formatted the card to be used as internal storage? Then backed it up and copied all the files to a new card? You can't even do that with the card installed as portable storage if you "move" apps to the card.

If you're going to change SD cards, all apps have to be physically in eMMC storage first. Apps on the SD card don't show in the SD card's directory, since they're just little chunks of data. And a card formatted as internal can't be copied to a PC.

I think you're mixing up a few non-mixable things.

 

[Questor11]

Rukbat, thanks for your comments. You wrote, "Apps on the SD card don't show in the SD card's directory, since they're just little chunks of data. And a card formatted as internal can't be copied to a PC."

Well, under the fusion storage it wasn’t possible to see which files were on the internal storage and which on the SD card; however, it appears that all the apps WERE in fact on the internal storage, because they all still work! I just don't see them anywhere now except in the app drawer.
It seems that only data files were being stored on the SD card (so I guess it wasn't true "fusion" storage, although the manufacturer claimed it was). In fact, one of the reasons I disabled the adoptable storage option when I replaced the SD card was that I wanted the ability to move some apps manually from the internal storage to the SD card, because the internal storage was almost full, and the SD card was mostly empty (according to the “Storage” display in my phone’s Settings menu).

Also, for clarification: when I wrote above that since the switch, newly installed apps can’t find their data files in the Android/obb folder, I’m talking about data files that I newly installed on the SD card at the same time as I installed the apps – of course I wouldn’t expect an old app that was working with fusion storage to find a data file on a new SD card.

 

[methodman89]

And if you'd run the app posted above you wouldn't need to guess.

 

[Rukbat]

Well, under the fusion storage it wasn’t possible to see which files were on the internal storage and which on the SD card; however, it appears that all the apps WERE in fact on the internal storage, because they all still work! I just don't see them anywhere now except in the app drawer.

And you won't. What's in the app drawer is a link to the app, not the app itself. The app is in a folder that only the app and superuser can see.

In fact, one of the reasons I disabled the adoptable storage option when I replaced the SD card was that I wanted the ability to move some apps manually from the internal storage to the SD card

Which is a particularly bad idea, for a few reasons. Apps update to internal storage, so you have to keep enough free space on internal storage to update the apps. And when the card goes bad (when, not if - SD cards have a limited number of write cycles), you can't reinstall the app (it's listed as being installed) but you can't uini9nstall it (because parts of it aren't available) - so you have to do a factory reset. And since all Android apps have to constantly keep their current state (stored wherever that part of the code sits), the app could be constantly writing to the SD card, killing it quickly.

because the internal storage was almost full, and the SD card was mostly empty (according to the “Storage” display in my phone’s Settings menu).

Google used to warn us to never install widgets to the SD card - because (due to code needed to make them widgets) they won't run from the SD card. Now, with apps being "developed" by using app-writing apps, the same holds true for any apps - they won't run from the SD card - so they're set to not allow temselves to be "moved".

Also, for clarification: when I wrote above that since the switch, newly installed apps can’t find their data files in the Android/obb folder

Because that folder is owned by another app. You'd have to modify platform.xml (or do it some other way - with Linux [and Android runs on Linux] there's always another way) to allow an app (like a file manager) to have full access to another app's folder. (Or you could just use chmod to change Othhers' permission to add read.)

 

[Questor11]

Thanks, Rukbat and methodman. I understand (some of) what you're saying:

"Apps update to internal storage, so you have to keep enough free space on internal storage to update the apps. And when the card goes bad (when, not if - SD cards have a limited number of write cycles)... And since all Android apps have to constantly keep their current state (stored wherever that part of the code sits), the app could be constantly writing to the SD card, killing it quickly." -- I figured this out when my SD card degraded to read-only; that's why I needed to change it, and it's also why fusion storage is obviously a bad idea in principle: it's sold as making the SD card available for app installation, but that's clearly not really a safe option (at least not for actively used apps).

"newly installed apps can’t find their data files in the Android/obb folder ... Because that folder is owned by another app." - this I don't understand, because I create a new subfolder in Android/obb for each app/data set. This worked fine before, not only on my current phone, but also on my old phone that had minimal internal storage capacity and ran KitKat, the apps and games worked perfectly.

"Install Data Size Explorer from the playstore and see what is using memory." -- How big is that app? The reason I haven't done this yet is because my phone's internal memory is nearly full, and I'm hesitant to download anything additional, even it if it might help free up some storage afterwards. It's a catch-22 situation for me...

Bottom line: I don't know exactly what changed when I switched the SD card (I was expecting problems with at least some of the apps, but I wasn't expecting the display permissions to change). Whatever, I can see that a factory reset is most likely in my phone's future.

 

[Rukbat]

it's sold as making the SD card available for app installation, but that's clearly not really a safe option (at least not for actively used apps).

It may be sold as makinf the SD card available for app installation, but it's designed to allow the phone to be used for a short time until you can replace t with a phone with more internal storage.

"newly installed apps can’t find their data files in the Android/obb folder ... Because that folder is owned by another app." - this I don't understand, because I create a new subfolder in Android/obb for each app/data set.

Which app owns Android? That app owns folders in the Android folder.

This worked fine before, not only on my current phone, but also on my old phone that had minimal internal storage capacity and ran KitKat, the apps and games worked perfectly.

KitKat is a special case. It was halfway between a free-for-all (and app could write anywhere prior to that) and a strict interpretation of Linux permissions rules.

Bottom line: I don't know exactly what changed when I switched the SD card

You switched from an internal card to a portable card. Without a full factory reset, there are no guaranties when you do that. And, without TWRP, backing everything up to do a FR is a bit of a pain. (not the reset so much, but the backing up and restoring.)

 

[Questor11]

Thanks for all your time and info, Rukbat.

I looked at TWRP, but it looks like that backs up EVERYTHING, including whatever settings are making it impossible for me to find my files since the switch -- so I don't know if that would help. Plus, frankly, I feel like I'm in over my head with this; I'm not a modder and (as you've surely realized) I don't know much about the inner workings of Android.

I would just really like to know what is using up all but 774 MB of my phone's nominal 16 GB of internal storage (of which 11.8 GB is actually available). When I add up all the space the "Storage" menu lists as being used by the different categories (Apps, Pictures, etc.), it adds up to only about 5.7 GB. So what is blocking the difference of approx. 5.3 GB? And whatever it is, I'd like to get rid of it. But to do that, I'd have to be able to find it, and so I've come full circle.
And I guess my only solution is a FR.

 

[methodman89]

If only there was a way to see.....