Unable to launch the IIS Express Web server

Failed to register URL “http://localhost:63647” for site application. Error description: The process cannot access the file because it is being used by another process (0x80070020).

1. Open project properties.
2. Choose “Web” on the left hand side.
3. Update the port number in the project URL. Then click yes if you want to update the virtual directory.
VisualStudio_Project URL

4. Save and restart Visual studio, then you should be good to go! =)


Section is locked (ipSecurity configuration)

Module IpRestrictionModule
Notification BeginRequest
Handler ExtensionlessUrl-Integrated-4.0
Error Code 0x80070021
Config Error This configuration section cannot be used at this path. This happens when the section is locked at a parent level. Locking is either by default (overrideModeDefault=”Deny”), or set explicitly by a location tag with overrideMode=”Deny” or the legacy allowOverride=”false”.

Update file: applicationhost.config (%userprofile%\documents\iisexpress\config\applicationhost.config)

Change line:
<section name=”ipSecurity” overrideModeDefault=”Deny” />

<section name=”ipSecurity” overrideModeDefault=”Allow” />

And in web.config use:

<ipSecurity allowUnlisted=”false” denyAction=”Unauthorized”>
<add ipAddress=”X.X.X.X” allowed=”true” subnetMask=”″ />