IIS Express will not start
To clarify John's comment - the directory will be something like C:\users\jmitchell\My Documents\IISExpress\config. I assume John is correct in that if it doesn't exist you would need to create the directory.
Alternatively the directory could already exist and just be corrupted. This is what I believe happened in my case. I had previously installed WebMatrix but ran into all sorts of issues today. After uninstalling IIS Express, Web Platform Installer, WebMatrix, and some SQL Server Management Objects, and then reinstalling WPI & WebMatrix, I came across this post.
I actually got IIS Express to run successfully after deleting the config directory mentioned above, and then re-running C:\Program Files (x86)\IIS Express>iisexpress.exe /trace:error
And I ONLY wasted two hours of my day on this! Thanks Microsoft!
using rider i had to remove this config file found here and that worked
\.idea\config\applicationhost.config
think this was caused when i removed VS
Check that the user its failing has a IISExpress\config folder in their home folder. If not then copy it over from the user where IISExpress is working. This is a common fault when the config files/folders are missing.
I has 2 things to do to make it work
try as everybody do
1.1. Delete all files in C:\{users}\My Documents\IIS Express\config
(Note: Don't worry it will re-create it automatically, if you afraid you can copy to some other place first)
If it still not work, try this below
2.1. Delete all files in {your project}\.vs\{your project}\config
(Note: .vs\ folder is hidden make sure you show hidden folder first)2.2. in Visual Studio > Right click on your Project > select Properties
2.3. Select "Web" Tab > in Project URL > change your port (Example: change from http://localhost:1096/ to http://localhost:1097/)
2.4. Save and run your Project again.