updating to 7.4 seemed to have done the trick, however, another error message is displayed now: This page is currently offline due to an unexpected error. We are very sorry for the inconvenience and will fix it as soon as possible.
Advice for developers and administrators:
Enable debug mode to get further information about the error.
This error is displayed underneath all the content, that now is showing.
It sounds like it’s a PHP configuration error, as pointed out by @texnixe. It might be worthwhile mentioning it to your service provider, in any case.
As PHP evolves and new versions come out, sometimes extensions become part of the ‘core’, while others that used to be installed by default are ‘dropped’. The way PHP accesses SQLite databases has changed a lot over the years, and in older versions of PHP, in order to access an SQLite database you needed to enable a special extension. In newer versions of PHP these extensions are now ‘default’ and part of the core. It could be that your service provider is still enabling the old SSLite extensions, in case they have developers with very old code, but these might be conflicting with the newer extensions which are part of the core.
Hello and sorry for the late answer, I first had time to check it now. It seems, like @texnixe said, that the sqlite3 was loaded twice. I contacted my host today, and we enabled sqlite3 in the extensions of the php version manager. Now my site runs fine on php 7.4.