Probably messed up upgrading

I've upgraded my Xerte server to 3.10 as I've always done.
Now when I enter
//server/xerte
I end up with
//server/xerte/setup.php
I thought perhaps I have forgotten to run upgrade.php so I entered
//server/xerte/upgrade.php
This is then changed to
//server/xerte/upgrade.phpsetup
which of course can't run.
I did a check whether there was any rewrite rule but there wasn't.
I renamed setup to setup.xx and tried again //server/xerte
I now get the message
Database setup failed (at least setup is not added to the url now).
I'm running Debian 10, Apache 2.4.38, PHP 7.3, MariaDB 10.3.29
Any help in figuring out what went wrong is much appreciated.

Redirection to setup normally only occurs if the database connection could not be established.

So please check if there is anything wrong in database.php. Check php database extensions.

You can also try to set $development to true in config.php (around line 43). Thist increases the error logging and might give you a clue in teh apache error.log.

Thank you for your advice.
I finally managed to solved the problem.
In fact there were two problems.

Problem 1:
The database user for the Xerte database was specified as 'username'@'127.0.0.1' however within MariaDB the user was known as 'username'@'localhost'. Hence, no connection was possible to the database as you already suspected. After changing this, Xerte seemed to work but I was unable to login. This was caused by the second problem.

Problem 2:
I have no idea what caused this but there were several tables in InnoDB format while the majority of the tables was in MyISAM format. The problem was with the InnoDB tables giving an error message they were not present within the engine. I deleted all tables and restored them all from an sqldump that was made when everything was still working. After that everything worked again.