I have SecNotes version 7.2 on my older cell phone.  When I transferred all my data to my new phone, the program transferred, but the data files didn't.  The app updated to version 9.0 on my new phone.

I'd like to transfer my data from my old phone to my new.  If I go into the settings on Ver. 7.2, it gives me an option to Backup, which it says will be in /storage/emulated/0/secnotes/secnotes.db.  If I do a manual backup, it first asks permission to "Replace existing backup?" and then tells me "All notes have been backed up!!"  However, when I attach my old phone to my computer, I can get to /storage/emulated/0 and that's it.  There is no /secnotes/secnotes.db below the "0".

How do I backup or copy my existing data from my old phone and old version of SecNotes, to my new phone and new version?

EDIT:  I did finally find the backup file on my old phone.  It was just under /secnotes/secnotes.db.  I copied it to my computer, and then copied it to the same folder on my new phone with Ver. 9.0  (even though it also talks about this "/storage/emulated/0" location, which doesn't exist there either).  I attempted to restore it.  It found the backup file and told me that the file is corrupted.

Internal memory is setup different by different phone vendors. The easiest way is to use cloud based backup. Please enable dropbox backup in the old phone (you need a dropbox account or create one .. its free). Secnotes will take a backup when you setup the account. Then in the new phone, enable dropbox backup. It will say a backup is already found and if you want to update. Choose yes and your notes will be transferred.

Both phones are made by the same company, LG, but that really shouldn't matter.  The backup file should be independent of the phone being used... the formatting for the backup file should be determined by YOUR software, not the phone's.  Either the old version of Sec Notes is saving a corrupt file, or the two versions of Sec Notes use incompatible formatting for the backups.  The new version of Sec Notes on my new phone is finding the backup file, it just can't open it.

Using Dropbox won't work, as my old phone appears to be too old to use Dropbox.  When I try to sign in to my Dropbox account, all of the available buttons are greyed out, except for installing the Dropbox app.  When I try to do that, it tells me that the app isn't compatible with my phone.

It appears my only choice is to copy all of my files by hand :-( .

@rick, you are right this is due to a change in the backup format done couple years ago.  This was to make it more secure by utilizing new android features. Android releases certain features only available on newer versions without backward compatibility. That's the reason android didn't allow secnotes upgrade to version 9.0 in your old phone. We rarely make such changes only when the advantages are too big for users. Normally, the app upgrades will take care of this and everything should be seamless.

Could you please try the following -

1. Uninstall the new version from the new phone. Copy the backup file again to the new phone.
   
2. Download the older setup from this link and install it - https://drive.google.com/file/d/1Mu2f5hXCuY5TENu9GwYc51_4p9oJO9eh/view?usp=sharing
3. Open the app and restore notes from the backup.
4. Close the app.
   
5. Go to play store, search sec notes and use the "Upgrade" option to upgrade to latest version.

When the new version of the app starts up, it will upgrade the backup to the new format and you should have all your notes as before. Please let me know if you find any issues.