The page you tried to view is not used by Blesta
You are seeing this page as a placeholder as page you visited is not used by Blesta.
For example WHMCS, Clientexec, WISECP, HostBill, BoxBilling have a built-in Announcements page. So when using these software the Announcements link in the footer will function. Blesta does not support Announcements by default so the link will return this page.
By default we have the theme setup with links for WHMCS which supports the most functionality/pages of any software integration options. The default Extras menu for example is for the WHMCS Marketconnect pages. These pages are unique to WHMCS, so if you are using different software the pages will return this page.

What To Do

As the page is not used by Blesta you should remove the link or button to this page from your theme. For example if the link is within a menu of the theme you can remove this via WordPress Admin > Appearence > Menus.
As WordPress is very powerful you add a lot of functionality to your website using plugins. For example Blesta does not support announcements out of the box. If you are using Blesta you could replace the announcements link in the footer with a link to your WordPress announcements (such as the blog).

How To Edit/Manage Software URLs

You can edit the default software URLs for your chosen software. For example if you are using custom htaccess rules to rewrite your Blesta URLs they may be different that the default we have set. You can edit default software URLs within the following theme file:
https://justvm.net/wp-content/themes/prosper/functions/software-integration/urls.php

Add Your Own URLs

You can also add your own URLs. Let’s say for example you are using WISECP and you are using a module to add a forum. You can either directly link to this forum within the theme or add the URL as a dynamic option to use. To add a URL you will need to add an array item to the following theme file:
https://justvm.net/wp-content/themes/prosper/functions/software-integration/urls.php