Hi Thomas,

Need to call

app.UseStaticFiles();

Try the following code.

1. Create a new extension Method (it's your choice)

   public static void ApplyRewriteRules(this IApplicationBuilder app)
   {
           using (StreamReader iisUrlRewriteStreamReader =
               File.OpenText("IISURLRewrite.xml"))
           {
               var options = new RewriteOptions()
                   .AddRedirectToHttpsPermanent()
               .AddIISUrlRewrite(iisUrlRewriteStreamReader);
   
   
           app.UseRewriter(options);
       }
       app.UseStaticFiles();
   } 
   
   
   

2. Call the created extension method ApplyRewriteRules before the app.UseUmbraco();

       //add custom iis rules
       app.ApplyRewriteRules();