Error with Visitor Groups when using Page with Shortcut to media item

Description

There is an issue related to creating visitor groups based on a visited page which has a shortcut configured for another content item.

Steps to reproduce

1. Create a page.
2. Set the shortcut to 'Shortcut to another content item' and select a media item (image or a GenericMedia).
3. Go to 'Visitor Groups' -> Create -> Site Criteria -> Visited page -> ... to select page.
4. Select the page to which you previously added the shortcut.

Expected: Can create the Visitor Group without removing the shortcut, and no popup error is displayed.

Actual: Get popup with error:
"Content with id 'XXXX' is of type 'Castle.Proxies.GenericMediaProxy' which does not inherit required type 'EPiServer.Core.PageData'."