Hi,

I'm in the middle of upgrading from 11 to 12, and I'm encountering a 500 error page after logging into the CMS, but can't find the actual error message anywhere, and can't turn the generic error page off.

While a lot of things aren't working yet, I managed to fix all compilation errors and got the CMS running for the first time. The first issue, is that after logging in on "util/Login", I'm redirected to to root page instead of /episerver/cms. Is there a configuration for that?

When I manually go to /episerver/cms after logging in, the CMS seems to load fine. After a second or two, it suddenly switches to this:

Weirdly though, I had no issues last week and the CMS was usable to the extent that I upgraded the solution for.

But now, I get this. There is not a single error message in the logs, nothing in the Windows Event Viewer (if that is even relevant anymore), and I have also enabled the developer exception page in my startup. I'm really running out of ideas how to view the actual error message.

There is a warning about a missing module: The modules finder couldn't find a directory at '/EPiServer/episerver-telemetry-ui'. Could that in any way be relevant? I can't seem to find anything online or in the code that references this.

If it helps, here is my Startup:

public class Startup
    {
        private readonly IConfiguration _configuration;
        private readonly IWebHostEnvironment _webHostEnvironment;

        public Startup(IConfiguration configuration, IWebHostEnvironment webHostEnvironment)
        {
            _configuration = configuration;
            _webHostEnvironment = webHostEnvironment;
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
            services.AddSession();
            services.AddRazorPages();
            services.AddHttpContextAccessor();
            services.AddCms();
            services.AddCmsAspNetIdentity<ApplicationUser>();
            services.AddCommerce();
            services.AddFind();
            services.AddSitemaps();
            services.AddSitemapsCommerce();

            services.AddNotFoundHandler(o =>
            {
                var connectionString = _configuration.GetSection("ConnectionStrings")["EPiServerDB"];
                o.UseSqlServer(connectionString);
                o.HandlerMode = FileNotFoundMode.On;
                o.Logging = LoggerMode.On;
                o.LogWithHostname = false;
            });

            services.AddOptimizelyNotFoundHandler(o =>
            {
                o.AutomaticRedirectsEnabled = true;
                o.AddOptimizelyCommerceProviders();
            });

            services.ConfigureApplicationCookie(options =>
            {
                options.LoginPath = "/util/Login";
            });

            if (_webHostEnvironment.IsDevelopment())
            {
                services.AddAdminUserRegistration(opt =>
                {
                    opt.Behavior = EPiServer.Cms.Shell.UI.RegisterAdminUserBehaviors.Enabled;
                });
            }
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseStaticFiles();
            app.UseRouting();
            app.UseAuthentication();
            app.UseAuthorization();
            app.UseSession();
            app.UseNotFoundHandler();
            app.UseOptimizelyNotFoundHandler();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapContent();
                endpoints.MapRazorPages();
            });
        }
    }