Sorry, for the late reply. This all happened while I was on holidays.
It turned out that the web hosting company did some changes in the configuration.
fileinfo and mysqlnd, pdo_mysql and mysqli were not present and inconsistent in version.
This was actually related to my other threat: https://forum.silverstripe.org/t/user-notice-mysqlnd-php-library-is-not-available-numeric-values-will-be-fetched-from-the-db-as-strings/3765?u=kimk