Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method widget_categorys::init() cannot be called statically in /var/www/html/wp-includes/class-wp-hook.php:324
Stack trace:
#0 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#1 /var/www/html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#2 /var/www/html/wp-includes/widgets.php(1862): do_action('widgets_init')
#3 /var/www/html/wp-includes/class-wp-hook.php(324): wp_widgets_init('')
#4 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#5 /var/www/html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#6 /var/www/html/wp-settings.php(695): do_action('init')
#7 /var/www/html/wp-config.php(98): require_once('/var/www/html/w...')
#8 /var/www/html/wp-load.php(50): require_once('/var/www/html/w...')
#9 /var/www/html/wp-blog-header.php(13): require_once('/var/www/html/w...')
#10 /var/www/html/index.php(17): require('/var/www/html/w...')
#11 {main}
  thrown in /var/www/html/wp-includes/class-wp-hook.php on line 324