Restore a 9.0 backup to 6.72 ?

[Fireword]

Hello guys
A month ago I sold my old ps4 fat in 9.0 not without first making a backup

Now I just bought a new ps4 slim in 6.70, updated it to 6.72 and tried to restore the backup through FTP
everything went well the only failed files were some web caches of 9.0
But once I closed the webexplorer the ps4 said that the database was corrupted, restarted itself and when it booted it restored the database nullifying and deleting all my backup

So my question is if there's any other way to restore my backup to 6.72
or to restore my saves i need to update to 9.0 mandatorily?
Thanks

 

[godreborn]

You need to change the user ID in the app.db or it will say that. You can change all occurrences with a hex editor.

 

[Fireword]

You need to change the user ID in the app.db or it will say that. You can change all occurrences with a hex editor.

thanks
Do i have to change the name of the app.db in my ps4 or the backup
and what name should it match or how it should be named?

 

[godreborn]

Use the decimal version of your user ID or you can find it in the savedata.db then replace with your new one. The user ID is what the tables are named after. Can't change them afaik without a hex editor, but it will change all occurrences with replace all.

 

[Fireword]

Sorry but I don't quite get it
Which one is my id in my savedata.db