Unable to restore .bak file

Hi guys,
New user here so sorry if this is in the wrong section (feel free to move).
I've been using an app to help with budgetting by tracking incomes and expenses for the last 6-7 years.
Anyway, I did something stupid a couple of weeks ago and deleted something accidentally so my immediate response was to restore the latest back up file from that morning but the app was empty after the restore.
I uninstalled and re-installed the app, rebooted my phone plus downloaded the app on another phone but the file wouldn't restore even though the app advised it has been restored successfully.
Tried to convert the .bak file to a CSV and could see over 14,00 rows of data which looked to be encrypted so quite illegible. I then looked at some .bak files from the same month and and the back up seemed to have been working as there were more data being added everyday. I've had a few phones since having the app and have always been able to restore data on the new phones. Also tried to see if I can restore the .bak file via SQL but the software couldn't even see it.
The app developers have ignored my emails since I've sent the .bak file so wondering if there's anything else I can do to try and get the file restored some other way or decrypt it somehow?
Thanks for your time in reading this.

PS: I'm not too technical so please use layman terms if possible.

Hi, welcome to Android Forums

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https://forums.androidcentral.com/sh...d.php?t=409154

Welcome to Android Central! Do you know what created that .bak file? Was it the app itself, or some other backup app/feature on your phone?

Giving the file another extension doesn't change what's in the file. .bak usually just means that it's a backup - of something. You have to find out what the original extension was and rename the file with that extension. The app isn't going to read a file of the wrong extension just because it originally created the file - "file creation app" isn't one of the things stored in a file's information.

Originally Posted by B. Diddy

Welcome to Android Central! Do you know what created that .bak file? Was it the app itself, or some other backup app/feature on your phone?

Hi B. Diddy,

Yes, the .bak file was created by the app itself (not sure if I am allowed to mention the name of it here).

The app was set up to take a daily back up and only keeps the last 30 days. Having looked at the size of the files, they were increasing ever so slightly everyday as I added more data into it.

Originally Posted by Rukbat

Giving the file another extension doesn't change what's in the file. .bak usually just means that it's a backup - of something. You have to find out what the original extension was and rename the file with that extension. The app isn't going to read a file of the wrong extension just because it originally created the file - "file creation app" isn't one of the things stored in a file's information.

Hi Rukbat,

Now that the developers are ignoring me, is there anyway of finding out what the original extension would have been?

Had a look at the file properties but only gives me the Name, Location, Type (which is unknown), File Size and Modified Time. Is there anywhere else I should be looking to give me clues?

How did you restore data for the app on other devices? Are you sure this .bak file is in the proper directory?

Originally Posted by redzhell

Now that the developers are ignoring me, is there anyway of finding out what the original extension would have been?

Not without uninstalling the app, then reinstalling it.

Had a look at the file properties but only gives me the Name, Location, Type (which is unknown), File Size and Modified Time. Is there anywhere else I should be looking to give me clues?

No, As I said, files don't tell you what app created them or what their name used to be.

Originally Posted by B. Diddy

How did you restore data for the app on other devices? Are you sure this .bak file is in the proper directory?

I emailed the .bak file from the original phone then downloaded it to the other device.

I then manually created a back up file on this new device to ensure that a new folder is created so I could see the directory of where files are being saved to and saved the emailed .bak file on this folder.

When restoring via the app, I could see the one I had manually created and the one with data on it so was positive that it was being saved in the correct place. I've had several phones since using this app and have been successful in transferring/restoring data before so not sure why it's not working this time round.

Originally Posted by redzhell

I emailed the .bak file from the original phone then downloaded it to the other device.

I then manually created a back up file on this new device to ensure that a new folder is created so I could see the directory of where files are being saved to and saved the emailed .bak file on this folder.

When restoring via the app, I could see the one I had manually created and the one with data on it so was positive that it was being saved in the correct place. I've had several phones since using this app and have been successful in transferring/restoring data before so not sure why it's not working this time round.

It's possible you were using different Android version while it got backed up to other phones ? Maybe this where issue is .

Originally Posted by Rukbat

Not without uninstalling the app, then reinstalling it.

Hi - OK I think we might have had our wires crossed here.

I've already uninstalled and re-installed the app. The original file was saved as a .bak file however, I took a copy of this and changed the extension to .CSV just to see if I could read any data from it but it just returned 14,000 rows of of what looks like encrypted data.

Originally Posted by mustang7757

It's possible you were using different Android version while it got backed up to other phones ? Maybe this where issue is .

Yes this could be possible however, I would have expected to be able to restore the file on to the original phone where the back up was created the same day I tried to restore it.

I only sent the file to another device in case my phone was being weird and wanted to ensure I didn't lose the file whilst I uninstalled/reinstalled the app on the original phone.

Originally Posted by redzhell

Yes this could be possible however, I would have expected to be able to restore the file on to the original phone where the back up was created the same day I tried to restore it.

I only sent the file to another device in case my phone was being weird and wanted to ensure I didn't lose the file whilst I uninstalled/reinstalled the app on the original phone.

Gotcha...so u still have the older device, should put back the file name on the back up also if you haven't. Does that app you use automatically looks for back ups ? Or you import it?

Originally Posted by mustang7757

Gotcha...so u still have the older device, should put back the file name on the back up also if you haven't. Does that app you use automatically looks for back ups ? Or you import it?

The file has been put back in the correct directory with the original file extension on the older device.

The app saves the back up files locally and automatically lists all the files that can be restored if they are saved in the correct folder.

If the files are encrypted, they may be using the phone's encryption, which varies by device. (Part of the encryption key is the phone's serial number, so that changes from phone to phone.) Only the developer can do anything at this point.

Originally Posted by Rukbat

If the files are encrypted, they may be using the phone's encryption, which varies by device. (Part of the encryption key is the phone's serial number, so that changes from phone to phone.) Only the developer can do anything at this point.

I agree there