Unicorn Login issue with Sitecore 9.2 Identity Server

In one of my projects, I have installed Sitecore 9.2 and integrated it with my Visual Studio solution code file everything was working fine. When I was trying to sync Unicorn items with Sitecore, and I found Unicorn.aspx page is not working.

After, I hit the Unicorn.aspx to sync Sitecore Items it shows error message Access Denied and You need to sign in to Sitecore as an administrator to use the Unicorn control panel . I selected the option Sign in to Sitecore as an administrator and it redirected me to the Sitecore Identity Server login page . I entered my username and password and it returned me to the Unicorn Control Panel page, but still, it was showing me the same error message as below:

Yes, I was able to log in to Sitecore and able to see my Sitecore Dashboard but not able to get access to Unicorn Control Panel. Unicorn.aspx serialization page was not showing.

Solution:

Lets perform the below steps for solution:

1. Use the latest version of Unicron using Nuget, I am using the latest stable version 4.1.1 .
2. Create a config file and paste the below piece of code into that. I have created and named z.unicorn.hotfix.config. You can give name as per your wishes, must insure it should be following the pattern as z.{file-name}.config .

   <configuration>
       <sitecore>
           <pipelines>
               <owin.cookieAuthentication.validateIdentity>
                   <processor type="Sitecore.Owin.Authentication.Pipelines.CookieAuthentication.ValidateIdentity.ValidateSiteNeutralPaths, Sitecore.Owin.Authentication">
                       <siteNeutralPaths hint="list">
                           <path hint="unicorn">/unicorn.aspx</path>
                       </siteNeutralPaths>
                   </processor>
               </owin.cookieAuthentication.validateIdentity>
           </pipelines>
       </sitecore>
   </configuration>
               

3. Drop this file under your include folder of Unicron that will be at below location <Sitecore-Project-root-path>\App_Config\Include\Unicorn
4. Run your Unicron control panel and see the result you will get as you expected (If not, then please restart IIS).

Happy Sitecoreing