Widget CSS Classes

The $domain parameter must be a single text string literal. Found: WCSSC_Lib::DOMAIN

Global variables defined by a theme/plugin should start with the theme/plugin prefix. Found: "$blog".

Function "get_sites()" requires WordPress 4.6.0, but your plugin minimum supported version is WordPress 3.3.0.

The use of function wp_get_sidebars_widgets() is forbidden

Hook names invoked by a theme/plugin should start with the theme/plugin prefix. Found: "active_plugins".

Processing form data without nonce verification.

Detected usage of a non-sanitized input variable: $_FILES['widget-css-classes-settings-import-file']['tmp_name']

Detected usage of a possibly undefined superglobal array index: $_FILES['widget-css-classes-settings-import-file']['tmp_name']. Check that the array index exists before using it.

In footer ($in_footer) is not set explicitly wp_enqueue_script; It is recommended to load scripts in the footer. Please set this value to `true` to load it in the footer, or explicitly `false` if it should be loaded in the header.

PHP file should prevent direct access. Add a check like: if ( ! defined( 'ABSPATH' ) ) exit;

Tested up to: 6.7 < 7.0. The "Tested up to" value in your plugin is not set to the current version of WordPress. This means your plugin will not show up in searches, as we require plugins to be compatible and documented as tested up to the most recent version of WordPress.

Missing "License" in Plugin Header. Please update your Plugin Header with a valid GPLv2 (or later) compatible license.