Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method WC_visibility_Tab::activate_filter() cannot be called statically in /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-includes/class-wp-hook.php:308 Stack trace: #0 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #1 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #2 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-settings.php(595): do_action('after_setup_the...') #3 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-config.php(114): require_once('/customers/e/6/...') #4 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-load.php(50): require_once('/customers/e/6/...') #5 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-blog-header.php(13): require_once('/customers/e/6/...') #6 /customers/e/6/a/ejimpex.eu/httpd.www/shopping/index.php(17): require('/customers/e/6/...') #7 {main} thrown in /customers/e/6/a/ejimpex.eu/httpd.www/shopping/wp-includes/class-wp-hook.php on line 308