title: Identityserver4 Login ValidateAntiForgeryToken
body: <p>I have identityserver4 working, but I am facing an issue I don't know how to resolve. I downloaded a sample project from their GitHub repo (<a href="https://github.com/IdentityServer/IdentityServer4.Templates" rel="nofollow noreferrer">https://github.com/IdentityServer/IdentityServer4.Templates</a>). Using their IdentityServer4InMem sample, I am able to replicate exactly what I am experiencing. </p>
  
  <p>If I run the project and open two tabs with the following url:
  <a href="http://localhost:5000/Account/Login" rel="nofollow noreferrer">http://localhost:5000/Account/Login</a></p>
  
  <p>If log in to tab 1, if I attempt to log in to tab 2 I get a HTTP ERROR 400.
  I've researched it has to do with the ValidateAntiForgeryToken, if I take off the annotation, I do not get the error. Of course I can not do that in production, so I am trying to find a solution.</p>