Issue: [4.1 Alpha 2] Area allowed content-types can trigger new page permission errors

1) Permission error problem

If an area has had content types restricted in "Can Contain Content-Types", this may prevent new pages from being added.

The issue only seems to occur if "Normal Pages" is not one of the allowed types.

For example, on my test site I have an area restricted to just Templates. When trying to preview a new template page, a standard XenForo no permission error is returned in an overlay: It seems Anonymous Pages has a similar issue, since I get a permission error on the VW XF demo in the Island Demo Area: https://www.vaultwiki.org/xf-wiki/in...&itemtypeid=19

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2) Confusing/buggy "Treat this page as" form section

Another issue when an Area doesn't allow "Normal Pages" is the "Treat this page as a: Template" checkbox is missing. If this was intended (since the Area doesn't permit non-Template pages), a FontAwesome checkbox icon (or disabled checkbox form element) would be good here.

If I set an Area's allowed types to "Normal Pages" and "Templates" (or Any Type), then the checkbox shows fine.

If I set an Area's allowed types to "Categories" and "Templates" (but not "Normal Pages), and then attempt to create a...

• Category, only Category is shown in "Treat this page as a" - no label or checkbox for Template
• Template, Category and Template are shown in "Treat this page as a". Category has a checkbox and label, Template only has a label.

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3) Related question (admin cp):
In the Area Manager, "Book Chapters" shows as a selectable option even if Book has been inactivated in Content Types. Is this behaviour as intended?
It appears as though the Anonymous Page content type (Un-Linkable) does get removed from Area Manager "Can Contain Content-Types" lists.