Could not load file or Assembly Microsoft.Identity.Model

[WebDBApps]

Hi,

I've deployed an ASP.NET MVC site to Plesk running on Windows Server 2012. The register and login links throw the following error:

Could not load file or assembly 'Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. Access is denied.

I've installed Windows Identity Foundation and framework 4.5 on this server. I also gave Plesk Admin and Plesk User full permissions to,the application directory. What other steps should I take to ensure an error free deployment?

Thanks,
Sid