While debugging a .NET MVC WebAPI project, I was getting the error, related to cross origin resource sharing:
No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘http://localhost:XXXXX’ is therefore not allowed access.
Once I added the following custom header to the IIS Express application host configuration, the errors disappeared.
<add name=”Access-Control-Allow-Origin” value=”*” />
<add name=”Access-Control-Allow-Headers” value=”Content-Type” />
I had to update the C:\Users\username\Documents\IISExpress\config\applicationhost.config file, by using Notepad++ (don’t forget to “Run as administrator”). You can also use AppCmd.exe, if command-line is your thing.
I also read updating the C:\Program Files (x86)\IIS Express\AppServer\applicationhost.config file can fix the problem, but this didn’t work for me.
Final result:
<httpProtocol>
<customHeaders>
<clear />
<add name=”X-Powered-By” value=”ASP.NET” />
<add name=”Access-Control-Allow-Origin” value=”*” />
<add name=”Access-Control-Allow-Headers” value=”Content-Type” />
</customHeaders>
…
</httpProtocol>