debug "Unknown Error" after upgrade from 3.0.3 to 4.1.0

[guilegatan]

I tried to upgrade from a working 3.0.3 version to 4.1.0:

I migrated the config.php to the new format, as well as my custom css and logo.
I made sure /tpl, /tpl_c and /uploads have correct r/w permissions.
I checked the database_schema/upgrade/4.0 folder, but the database seems to be identical in 4.x to 3.0.3

Whenever I try to open the application, I get an "Unknown Error" message, instead of the login page. See screenshot.
I can't find any logs (the log-folder, though writable, stays empty). Apache does not log anything either. I enabled PHP-errors, but nothing there either.

Any help appreciated!

[guilegatan]

my fault. set log-level to "debug". Now I get this in the logs:

[2026-02-12T12:40:15.476123+00:00] app.ERROR: [User= ()] Uncaught exception: TypeError: mysqli_select_db(): Argument #1 ($mysql) must be of type mysqli, false given in /var/www/html/librebooking/lib/Database/MySQL/MySqlConnection.php:42 Stack trace: #0 /var/www/html/librebooking/lib/Database/MySQL/MySqlConnection.php(42): mysqli_select_db() #1 /var/www/html/librebooking/lib/Database/Database.php(23): MySqlConnection->Connect() #2 /var/www/html/librebooking/Domain/Access/AnnouncementRepository.php(11): Database->Query() #3 /var/www/html/librebooking/Presenters/LoginPresenter.php(131): AnnouncementRepository->GetFuture() #4 /var/www/html/librebooking/Pages/LoginPage.php(156): LoginPresenter->PageLoad() #5 /var/www/html/librebooking/Web/index.php(22): LoginPage->PageLoad() #6 {main} [File=/var/www/html/librebooking/lib/Common/Logging/ExceptionHandler.php,Line=19] []

[guilegatan]

I am an idiot. The database-password was wrong. Sorry.

[JohnVillalovos]

I am an idiot. The database-password was wrong. Sorry.

No worries. One of the reasons that I just added this 4f48ec2 which will be in the next release.