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C# User Authentication with ASP.NET Identity Introducing ASP.NET Identity Installing Identity

Cheryl Lewman
Cheryl Lewman
9,080 Points
Posted by Cheryl Lewman
Cheryl Lewman
9,080 Points

Error after loading Owin Startup

I'm getting this error after uploading Owin.

Server Error in '/' Application.

The following errors occurred while attempting to load the app.

  • No assembly found containing an OwinStartupAttribute.
  • No assembly found containing a Startup or [AssemblyName].Startup class. To disable OWIN startup discovery, add the appSetting owin:AutomaticAppStartup with a value of "false" in your web.config. To specify the OWIN startup Assembly, Class, or Method, add the appSetting owin:AppStartup with the fully qualified startup class or configuration method name in your web.config. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.EntryPointNotFoundException: The following errors occurred while attempting to load the app.

  • No assembly found containing an OwinStartupAttribute.
  • No assembly found containing a Startup or [AssemblyName].Startup class. To disable OWIN startup discovery, add the appSetting owin:AutomaticAppStartup with a value of "false" in your web.config. To specify the OWIN startup Assembly, Class, or Method, add the appSetting owin:AppStartup with the fully qualified startup class or configuration method name in your web.config.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

1 Answer

henrikdk
henrikdk
8,935 Points
henrikdk
henrikdk
8,935 Points

Hi Cheryl, or anyone looking to solve this issue themselves. This is more than two years after the questions was asked, so I am just posting this for anyone looking to solve this in the future. I had this issue and only just now found the solution.

1) In the web.config file, under <appSettings>, add the following: <add key="owin:AutomaticAppStartup" value="false"/>

2) Right click in solution explorer, and select "Add item", to add a file to the root folder. Here, find and add an "OWIN Startup class".

The second step might be enough on its own. I just mention the first step, as it was mentioned in most threads about this issue.

I hope this will help someone. Better yet, I hope Treehouse adds it to the notes of the "User Authentication with ASP.NET Identity" course.

Josh Holton
Josh Holton
7,403 Points
Josh Holton
Josh Holton
7,403 Points

Thank you! This "fix" still solved the issue in 2024.