Error 403 Forbidden - Invalid signature

[Admin]

Right now, I don’t see any SSL error, but a blank page instead. The Network tab in my browser says the response code is 500, which usually means your PHP code crashed.

Please see this article for information on how to get started with fixing this:

Http error 500

When trying to access your website, you may see a page which returns the status code “500”. In Google Chrome, you’ll see a page with the error code HTTP ERROR 500. There are typically two reasons which can cause this error: The PHP code has crashed. The .htaccess file contains invalid rules. Here are some things you can try to debug and fix this. Fixing crashing PHP code A HTTP ERROR 500 simply tells you that the PHP code has crashed, but gives no information as to why it has crashed. Gett…