Keritaf Keritaf - 6 months ago 55
ASP.NET (C#) Question

VS 2012 can't load project which uses IIS with custom binding host - thinks it's using IIS Express

I have an ASP.NET project which uses IIS. IIS site is configured to use custom binding host name. Project file contains following settings:

<FlavorProperties GUID="{349c5851-65df-11da-9384-00065b846f21}">

When project is configured in such a way, I can access the site from
and VS automatically attaches to IIS worker process when debugging.

When I reload project (either by closing/reopening solution or by unload/reload in project context menu), something unexpected happens. Project fails to load,
(load failed)
is displayed to the right of project name in solution explorer and message box is shown with the following message (it's also displayed in the Output window):

The URL '' for Web project 'Some.Asp.Net.Project'
is configured to use IIS Express as the web server but the URL is currently
configured on the local IIS web server. To open this project, you must use
IIS Manager to remove the bindings using this URL from the local IIS web server.

I have tried removing project site configuration from IIS Express
file, but it didn't help.

I don't encounter this problem when mapping project to IIS Application under default site.

VS version is Ultimate 2012 Update 3.


Opening as an Administrator didn't fix the problem for me. What fixed it for me was opening both the .csproj and csproj.user files and ensuring that both had UseIISExpress set to false.

In my case, the .csproj.user file was overriding the .csproj file event though SaveServerSettingsInUserFile was marked false.

<Project ToolsVersion="12.0" xmlns="">
    <!-- ... -->