Hello Göran,
issues related to f0f will keep appearing until we phase the f0f lbrary out of our code. These are just messages explaining that the code is deprecated. These are not errors and don't affect the functionannlity of your site.
To get rid of the messages, turn off error reporting on your site, or better:
set error reporting to 'System default' and make sure your PHP php.ini file contains:
error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT
This will make sure you still get notified for errors but will prevent deprecated messages to appear and populate your site.