Ошибка — not configured to be debugged, хотя debug = "true" в файле Web.config. При попытке открыть страницу, вводя ее адрес в ИЭ — ошибка парсинга:

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.

Source Error:


Line 101: -->
Line 102:
Line 103: <authentication mode="Forms">


или authentication mode = "windows", никакой разницы

Здравствуйте, gaidar,

Это и была причина, спасибо за совет.