Hi,

I am migrating my .net framework application from version 11 to 12, the application is working fine in my localhost. But when i deployed the same in DXP Intergation environement(https://intecore.connectinvest.com/ ref URL) getting below error message when i am trying to login.

Refer below error logs:

2025-02-20T12:54:22.174279598Z     fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[1]
2025-02-20T12:54:22.174308284Z           An unhandled exception has occurred while executing the request.
2025-02-20T12:54:22.174313332Z           System.InvalidOperationException: Headers are read-only, response has already started.
2025-02-20T12:54:22.174317522Z              at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpHeaders.ThrowHeadersReadOnlyException()
2025-02-20T12:54:22.174321486Z              at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpResponseHeaders.Microsoft.AspNetCore.Http.IHeaderDictionary.set_SetCookie(StringValues value)
2025-02-20T12:54:22.174325802Z              at Microsoft.AspNetCore.Http.ResponseCookies.Append(String key, String value, CookieOptions options)
2025-02-20T12:54:22.174329533Z              at Microsoft.AspNetCore.CookiePolicy.ResponseCookiesWrapper.Append(String key, String value, CookieOptions options)
2025-02-20T12:54:22.174333473Z              at EPiServer.Framework.DependencyInjection.Internal.VisitorGroupResourceFilter.OnResourceExecutionAsync(ResourceExecutingContext context, ResourceExecutionDelegate next)
2025-02-20T12:54:22.174337780Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
2025-02-20T12:54:22.174342504Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeNextResourceFilter()
2025-02-20T12:54:22.174346614Z           --- End of stack trace from previous location ---
2025-02-20T12:54:22.174350029Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
2025-02-20T12:54:22.174353530Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
2025-02-20T12:54:22.174357183Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
2025-02-20T12:54:22.174360657Z           --- End of stack trace from previous location ---
2025-02-20T12:54:22.174363902Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
2025-02-20T12:54:22.174367523Z              at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
2025-02-20T12:54:22.174372620Z              at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
2025-02-20T12:54:22.174376594Z              at UnknownActionMiddleware.InvokeAsync(HttpContext context) in C:\Tools\ConnectInvest\ConnectInvestWeb\ConnectInvest.Core.Shared\UnknownActionMiddleware.cs:line 28
2025-02-20T12:54:22.174398097Z              at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
2025-02-20T12:54:22.174401734Z              at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
2025-02-20T12:54:22.174405403Z              at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
2025-02-20T12:54:22.174408882Z              at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
2025-02-20T12:54:22.174412937Z              at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
2025-02-20T12:54:22.177504246Z     fail: Microsoft.AspNetCore.Server.Kestrel[13]
2025-02-20T12:54:22.177528180Z           Connection id "0HNAHIIUQ23IE", Request id "0HNAHIIUQ23IE:00000009": An unhandled exception was thrown by the application.
2025-02-20T12:54:22.177533596Z           System.InvalidOperationException: Headers are read-only, response has already started.
2025-02-20T12:54:22.177537936Z              at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpHeaders.ThrowHeadersReadOnlyException()
2025-02-20T12:54:22.177542456Z              at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpResponseHeaders.Microsoft.AspNetCore.Http.IHeaderDictionary.set_SetCookie(StringValues value)

And, below is my Startup configuration for Indentity:

// Configure cookie authentication
services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = CookieAuthenticationDefaults.AuthenticationScheme;
    options.DefaultSignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = CookieAuthenticationDefaults.AuthenticationScheme;
})
.AddCookie(options =>
{
    options.LoginPath = new PathString("/UserAccount/Login");
    options.LogoutPath = new PathString("/UserAccount/LogOff");
    options.Cookie.HttpOnly = true;
    options.Cookie.SecurePolicy = CookieSecurePolicy.Always;  // Ensure cookies are only sent over HTTPS
    options.ExpireTimeSpan = TimeSpan.FromHours(5);  // Use your 'rememberMePeriod' here
    options.SlidingExpiration = false;

    // Identity validation (security stamp validation every 5 minutes)
    options.Events = new CookieAuthenticationEvents
    {
        OnValidatePrincipal = SecurityStampValidator.ValidatePrincipalAsync
    };
});
// Add authorization policies if needed
services.AddAuthorization(options =>
{
    options.AddPolicy("CmsAccess", policy =>
        policy.RequireRole("CmsAdmins", "CmsEditors", "WebAdmins", "WebEditors"));  // Required roles for accessing CMS
});

services
 .AddCmsAspNetIdentity<ApplicationUser>()
 .AddCms()
 .AddFind()
 .AddEmbeddedLocalization<Startup>();

// Ensure correct registration of ApplicationDbContext for Optimizely Identity
services.AddDbContext<ApplicationDbContext<ApplicationUser>>(options =>
options.UseSqlServer(Configuration.GetConnectionString("EPiServerDB")));  // Ensure your connection string is correct

Please suggest where i am missing.

Many thanks.