Visual Studio 2015 / IISExpress change SSL port

I had the same situation with 2 projects. Visual Studio 2015 correctly assigned differing URL port numbers for HTTP but mapped both projects to 44300 for HTTPS. AFAIK the applicationhost.config in .vs\config seems to define the IIS Express environment and tell IIS Express how to behave when invoked. This information doesn’t feedback into Visual Studio. … Read more

Force IIS Express to Classic Pipeline Mode

In Visual Studio 2010 select the Web Application project node in Solution Explorer then either: Press F4 or Navigate to View -> Properties Window or press F4 Important: Don’t Right-click -> Properties from the right-click context menu for the project node in solution explorer because that will show the Property Pages for the project which … Read more

IIS express: Cannot add duplicate collection entry of type ‘add’ with unique key attribute ‘name’ set to

I think IIS Express probably has 2 <application>-blocks and both will be pointing to the same physicalPath. Go to the IIS Express config file in: My Documents\IISExpress\config\applicationhost.config Search for NewProjectName Change the physicalPath for the root application to something else. Point it to an empty folder. Should look something like this: <site name=”NewProjectName” id=”1″> <application … Read more

IIS Express is automatically disabling anonymous authentication for my project, why?

It was because for some reason, this was in my csproj file: <IISExpressAnonymousAuthentication>disabled</IISExpressAnonymousAuthentication> Setting it to enabled fixes the issue (it can also be done from Visual Studio, select project, F4, set Anonymous Authentication in the properties grid to Enabled).

Visual Studio 2013 gives “Cannot add duplicate collection entry of type ‘mimeMap’”

The issue was that when I switched to Visual Studio 2013, the web server used for debugging changed. Visual Studio 2013 uses IIS Express by default. Although Visual Studio 2010 SP1 supports IIS Express, my installation was still using the default Visual Studio Development server. Like IIS 7, Visual Studio Development Server did not define … Read more

IISExpress 8 Cannot read configuration file redirection.config

I had a similar issue to @Myles J but renaming %userprofile%\Documents\IISExpress\config\applicationhost.config didn’t work. What I had to do was the following: Close Visual Studio. Rename the %userprofile%\Documents\IISExpress\config directory. Start Visual Studio again. The %userprofile%\Documents\IISExpress\config directory will be recreated with the default config files. Copy the original applicationhost.config file over the autogenerated one. Before anyone asks: … Read more