System.Security.SecurityException from a .NET website deployed in Web Server

In some cases while you have uploaded the compiled and published release files of your ASPNETMVC web application or ASPNET Web Application in Godaddy or any other hosting provider, you might have encountered an error which states “System.Security.SecurityException: Request for the permission of type ‘System.Security.Permissions.ReflectionPermission, mscorlib, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089’ failed.” might be because partial or medium trust is not supported for Microsoft.Owin.Host.SystemWeb package since this package helps in running OWIN middlewares on IIS integrated pipeline and the assembly does reflection to detect and load OWIN Startup class.

This kind of issue will occur when you build an MVC5 application with OWIN Startup class included having OWIN package installed. Below is the typical way the application error shown when you make <customErrors mode = “Off” /> in Web.Config file.


In order to resolve this issue you need to provide <trust level = “Full”/> under System.Web  section in Web.Config file

  <authentication mode="None" />
  <compilation debug="true" targetFramework="4.5" />
  <httpRuntime targetFramework="4.5" />
  <customErrors mode="Off"/>
  <trust level="Full" />

Hope this helps to my fellow developers if you are facing the same scenario somewhere


  1. Oh my goodness! Impressive article dude! Thanks, However
    I am experiencing problems with your RSS. I don’t understand why I cannot join it.
    Is there anybody getting identical RSS problems?
    Anyone who knows the answer will you kindly respond? Thanx!!


  2. After checking out a number of the articles on your web site, I truly like your way of blogging.
    I saved as a favorite it to my bookmark site list and
    will be checking back soon. Please visit my web site as well and let me know your opinion.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.