Communitydm80提出了一个问题：IIS 7.5 no images css js showing，或许与您遇到的问题类似。
Okay here's what I did to resolve my issue.
Since my app files are in a file share the Anonymous user account couldn't access them. This is because by default IUSR account is used for Anoymous user. In IIS->Site->Authentication set Anonymous Authentication to Application Pool Identity if you have created a custom app pool OR you can specify an account.
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\caspol.exe -m -ag 1 -url "file:////\computername\sharename*" FullTrust -exclusive on