Asp Net Образец ядра 3 с сервисом 503 недоступен

Question

При создании нового ASP. NET Core Web Application с использованием реакции и. Net Core 3.0 или 3.1 в Visual Studio и запуске приложения на странице отображается:

503 Сервис Недоступно

Не удалось подключиться к серверу localhost

• Я использую windows 10 professional and visual studio 2019.
• Ошибка происходит в IIS Express и kestrel.
• На другом компьютере это работает нормально.
• Создание шаблона с помощью «Веб-приложения (Model-View-Controller)» работает.
• вызов API работает (https://localhost: 5001 / WeatherForecast ).

Я устраняю неполадки при миграции в проект с As pNet Core 2.2 на 3.0 с той же ошибкой Я проверил, будет ли работать шаблонный проект, и обнаружил, что ошибка не указана c для миграции. Выяснение, почему шаблон не работает, вероятно, решит ошибку при миграции.

Редактировать:

• Отключение брандмауэра не решило проблему.

Вот журнал отладки для попытки открыть страницу:

dbug: Microsoft.AspNetCore.Server.Kestrel[39]
      Connection id "0HLTKHV201G3Q" accepted.
dbug: Microsoft.AspNetCore.Server.Kestrel[1]
      Connection id "0HLTKHV201G3Q" started.
dbug: Microsoft.AspNetCore.Server.Kestrel[39]
      Connection id "0HLTKHV201G3R" accepted.
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
      Request starting HTTP/1.1 GET http://localhost:5000/
dbug: Microsoft.AspNetCore.Server.Kestrel[1]
      Connection id "0HLTKHV201G3R" started.
trce: Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware[2]
      All hosts are allowed.
dbug: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[4]
      The request path / does not match a supported file type
dbug: Microsoft.AspNetCore.Routing.Matching.DfaMatcher[1000]
      No candidates found for the request path '/'
dbug: Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware[2]
      Request did not match any endpoints
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
      Request finished in 27.156ms 503 text/html; charset=UTF-8
dbug: Microsoft.AspNetCore.Server.Kestrel[10]
      Connection id "0HLTKHV201G3Q" disconnecting.
dbug: Microsoft.AspNetCore.Server.Kestrel[2]
      Connection id "0HLTKHV201G3Q" stopped.
dbug: Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets[6]
      Connection id "0HLTKHV201G3Q" received FIN.
dbug: Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets[7]
      Connection id "0HLTKHV201G3Q" sending FIN because: "The Socket transport's send loop completed gracefully."
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
      Request starting HTTP/1.1 GET http://localhost:5000/favicon.ico
trce: Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware[2]
      All hosts are allowed.
dbug: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[5]
      The request path /favicon.ico does not match an existing file
dbug: Microsoft.AspNetCore.Routing.Matching.DfaMatcher[1000]
      No candidates found for the request path '/favicon.ico'
dbug: Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware[2]
      Request did not match any endpoints
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
      Request finished in 19.8075ms 503 text/html; charset=UTF-8
dbug: Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets[6]
      Connection id "0HLTKHV201G3R" received FIN.
dbug: Microsoft.AspNetCore.Server.Kestrel[10]
      Connection id "0HLTKHV201G3R" disconnecting.
dbug: Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets[7]
      Connection id "0HLTKHV201G3R" sending FIN because: "The client closed the connection."
dbug: Microsoft.AspNetCore.Server.Kestrel[2]
      Connection id "0HLTKHV201G3R" stopped.