Problem : Swagger UI Not Accessible
Description: Swagger UI documentation page is not loading after deployment to MonsterASP hosting. It works correctly on local development environment.

Current Implementation
Program.cs (Middleware Configuration):



if (app.Environment.IsDevelopment() || app.Environment.IsProduction())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();


app.UseCors("AllowAllOrigins");
app.UseAuthentication();
app.UseAuthorization();

app.MapHub<NotificationHub>("/notificationHub");

app.MapControllers();

app.Run();

CORS Configuration (ApiServiceCollectionExtensions.cs):

services.AddCors(options =>
{
    options.AddPolicy("AllowAllOrigins", builder =>
    {
        builder
            .SetIsOriginAllowed(_ => true)
            .AllowAnyHeader()
            .AllowAnyMethod()
            .AllowCredentials();
    });
});

The Hub Implementaion

[Authorize]
public class NotificationHub : Hub
{
    public override async Task OnConnectedAsync()
    {
        var userId = Context.User?.FindFirst(ClaimTypes.NameIdentifier)?.Value;
        
        if (!string.IsNullOrEmpty(userId))
        {
            await Groups.AddToGroupAsync(Context.ConnectionId, userId);
        }

        await base.OnConnectedAsync();
    }

    public override async Task OnDisconnectedAsync(Exception? exception)
    {
        var userId = Context.User?.FindFirst(ClaimTypes.NameIdentifier)?.Value;
        
        if (!string.IsNullOrEmpty(userId))
        {
            await Groups.RemoveFromGroupAsync(Context.ConnectionId, userId);
        }

        await base.OnDisconnectedAsync(exception);
    }

}

The Notification Service :


public class NotificationService : INotificationService
{

    private readonly IHubContext<NotificationHub> _hubContext;

    public NotificationService(IHubContext<NotificationHub> hubContext)
    {
        _hubContext = hubContext;
    }

    public async Task SendNotificationToUser(string userId, string message)
    {
        await _hubContext.Clients.User(userId).SendAsync("ReceiveNotification", new { message });
    }
}

Application Details
• Framework: ASP.NET Core 9.0