database connection lost after update

[digikam_user.login at mobius.unbox.at]

I updated DK three das ago. At the first start I got a message, that the 
conversion of my database failed. digikam opened the configuration panel 
for database-connection....

When I launch digikam in zsh I get this:


~ % /Applications/digikam.org/digikam.app/contents/MacOS/digikam
qt.svg: QSvgHandler: Image filename is empty
qt.svg: QSvgHandler: Image filename is empty
qt.qpa.fonts: Populating font family aliases took 124 ms. Replace uses 
of missing font family "Bitstream Vera Sans" with one that exists to 
avoid this cost.
digikam.coredb: Core database: cannot process schema initialization


digikam is installed on MacOS Tahoe 26.5.2, my collection is on an QNAP 
TS431 with mariadb 5.5.57.

I assume, mariadb is too old....? Is that right?

QNAP provides no updates for mariadb....

best regards...

Uwe