I moved the site to a different hosting with PHP v5.4.45 in order to still use WP Statistics.
Thanks for the swift reply.
@blcsue, how did you solve it?
I’ve got the same error message.
The web should be running on PHP 5.3.29
(running a higher version of PHP broke some of the sites still running on the hosting) 🙁
Any solution (except downgrading the plugin)?