I have a website running on ASP.NET MVC 4.5.2. I have an IdentityServer4 server running but when I try and authenticate against it I get an: invalid_request I googled a bit but I can’t find a solution. Finally, I found the way. First, in your IdentityServer4 you have to create a new client: public static IEnumerable GetClients() { return new List<client> { new Client { ClientId = “yourid”, AllowedScopes = new List<string> { “openid” }, AllowedGrantTypes = GrantTypes.Hybrid, RedirectUris = new List { “https://yoururl/signin-oidc” }, } } } When you…