In VS 2012, I am attempting to create an MVC 4 web application with jQuery calls to a Web API project. (Other devs will be consuming the API with our current, native app, a
I had the same problem and have found a solution from here:
forums.asp.net
The fix is to do the following:
In your solution file, click properties go to the Startup project node (if it is not already selected)
Next select Multiple startup projects. Select your website and your webservice and in the Action column make sure both of them have "Start" selected.
Now when you debug your website and put a break point in your webservice, it should hit the break point.
Coming late to the party but in case anyone else is looking for a solution, this is what was best for me: Set the Api project up to be the starting project (I needed to limit to one startup so that I could flip between browsers more easily). After firing up the service project, right click on the web/ui project and select debug, start new instance. You'll have both running and you'll seamlessly step from web to api.
I had a similar problem with my web api project. My solution consisted of an angular front end with 2 web api projects on the backend. One web api project handled "authorization" and the other handled "resources". I used the following tutorial by Taiseer Joudeh as a starting point:
http://bitoftech.net/2014/09/24/decouple-owin-authorization-server-resource-server-oauth-2-0-web-api/
Breakpoints worked on the "authorization server"... but not on the "resource server". I compared the packages from the two projects to see what was different. Once I added "Microsoft.AspNet.WebApi.Cors" to the "resource server" project, the breakpoints starting working.