Kentico 12 page tab HTTPS error

I've configured my local environment to use SSL and since I get the error message in the page tab:

This feature is currently unavailable because the Kentico administration application is using secured HTTPS protocol. To enable this feature, the MVC application must be configured to also use HTTPS.

Both the MVC and Admin site are configured to work on HTTPS. I've followed the docs and added the Global filter to the Global.asax file

GlobalFilters.Filters.Add(new RequireHttpsAttribute());

and checked the box in setting so the admin interface is only access on HTTPS but no joy.

I've also tried added a rewrite rule to force the page onto https but again no joy.

Does anyone else have this issue?

Cheers James