Swagger UI page is blank on localhost IISExpress SSL URL

Question

I am developing a v5.0.6 ASP.NET Core WebApi and included Swashbuckle.AspNetCore Swagger with SwaggerUI enabled. I am developing with Visual Studio 2019 v16.10.0 on Windows 10 Version 21H1 (OS Build 19043.1023). Settings within the project properties are:

IISExpress App URL: http://localhost:64870
IISExpress Enable SSL URL: https://localhost:44387/
Console http://localhost:5000 and http://localhost:5001
If I start the WebApi from VS2019 and it comes up with URL 'https://localhost:44387/' the SwaggerUI page is completely blank but the WebApi can be accessed and data can be retrieved So I know the WebApi is working as it should. I can access the WebApi from any of the other URLs and the SwaggerUI page is displayed as it should be. It is only the IISExpress SSL URL of 'https://localhost:44387/' that has the empty page. I have spent hours working on this issue with no solution.

But the URL localhost:44387/swagger/v1/swagger.json displays data for swagger as it should. It is only the UI that is not working on IISEXpress SSL.

Has anyone seen this issue and has a solution.

Steve

Answer 1

Update: The latest version of Swashbuckle.AspNetCore Swagger v6.1.5 seeems to have fixed this issue.

Answer 2

Make sure your "launchUrl" setting in launchSettings.json are correct and matches your configuration. I use the standard Web API template of "swagger". Share your configuration if you still need help.

  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },

app.UseSwaggerUI(c => {
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "WebApiDemo v1");
    c.RoutePrefix = "swagger";
});

Answer 3

I want to deploy API those , I developed in asp.net core 5. but unable to fix it.
I have installed every thing but getting error on it

https://www.yardim.pk

Thanks,

Answer 4

Well this line ' "launchUrl": "swagger",' was missing in my launchSettings.json and my c.RoutePrefix was set to string.empty. Everything else was exactly the same. I made those two changes and no chnages in SwaggerUI display. Evrthing thing works as it should other than a blank page when running on IISExpress SSL localhost URL.

Answer 5

Hi @Orgbrat ,
Is your swagger middleware configured correctly?like this:

public void ConfigureServices(IServiceCollection services)  
{  
    // Register the Swagger generator, defining 1 or more Swagger documents  
    services.AddSwaggerGen(c =>  
    {  
        c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API", Version = "v1" });                  
    });  
    services.AddControllers();  
}  

This adds the Swagger generator to the services collection.
In the Configure() method, let’s enable the middleware for serving the generated JSON document and the Swagger UI:

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)  
{  
    // Enable middleware to serve generated Swagger as a JSON endpoint.  
    app.UseSwagger();  
    // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),  
    // specifying the Swagger JSON endpoint.  
    app.UseSwaggerUI(c =>  
    {  
        c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");  
    });  
}  

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