Getting Access is Denied for DotNetCompilerPlatform only on IIS - works on localhost

I have an existing C# Web Forms, Linq to SQL Project. I'm adding an MVC Project to it to upgrade a portion of the code, and this references the same Data Access (Linq to SQL Project).

Everything works fine on my localhost. However, when I added it to IIS 10 (locally), it gives a "Could not load file or assembly Microsoft.CodeDom.Providers.DotNetCompilerPlatform... Access is Denied" error.

I merely added another item to the Default Website. I already have the Web Forms root on another item there, and that works fine. So, the only different appears to be which root folder is being accessed.

Other Information

• MVC Project targets 4.7.2, Web Project targets 4.6.1, Data Access targets 4

Any ideas?

The Error also shows this:

WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure logging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Stack Trace:

[HttpException (0x80004005): Could not load file or assembly 'Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. Access is denied.] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +523 System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +107 System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +688