phpList 3.3.1 to 3.3.3 update problem

My data does not appear. It’s like a new installation

I followed the procedure:

Backup my database
Copy my config.php file in a safe place
Download the latest version of phpList
Overwrite all of the code of the current version with the new one. 
Copy my config.php back
Login to the phpList admin pages and click the “upgrade” link
“Verify database structure” page to check that my database structure is correct

Everything seems OK, but the setup is blank. No users, attributes, campaign…
Although all the data appears in the database.

Do you have any idea of a solution

My config:
Ubuntu 16.0.4
PHP 7.0

I have only one admin user and all my precedent data configuration is visible in database (attributes, users, campagnes, etc …
But they are not visible in phplist interface.
I have tried to restore my backup Lists directory but without success.
All my previous work would be lost?

@thefree Possibly the php version that you are running is earlier than 5.6. See this topic for a possible solution Blank Page on upgrade to 3.3.2 and 3.3.3 - Please help!

Hello Duncan,
My config:
-Ubuntu 16.0.4, PHP 7.0
I don’t have a blank page.
Everything works a priori normally but the configuration is blank, like a new installation. However, my configuration is well in the BDD. (attributes, lists, template…