The URL could not be accessed because of Internet Explorer security settings

I just ran into this when trying to validate a SharePoint (2010) site from within CRM2011. Here’ what I did to solve it:

• Add the site you’re trying to validate against (https://sp.contoso.com) to your trusted sites in IE.
• Drop the trusted sites level to Low
• Click validate (which then the site should validate)
• Make sure to set your trusted sites back up to **Medium **when done.

Hope this helps!