AppThemes Updater I have an error message
Hello in admin when the plugin is active AppThemes Updater I have an error message
Strict Standards: call_user_func_array() expects parameter 1 to be a valid callback, non-static method APP_Theme_Upgrader::display_warning() should not be called statically in /var/www/vhosts/crautosgratis.com/httpdocs/wp
-includes/plugin.php on line 525
How to solve this problem?