Error message in Admin Dashboard after activation

Hello,

I’d like to test your plugin. Unfortunately, I have this message after activating in :

Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method Facetious_Widget::register() should not be called statically in /Applications/MAMP/htdocs/docteo/wp-includes/plugin.php on line 496

I have deactivate all my plugins.

Any help would be much appreciated ! 🙂

Mat

https://wordpress.org/plugins/facetious/