After installing OWIN or Service API, a login pop up will be displayed when visiting the Find configure page(https://dl.dropboxusercontent.com/u/19725692/Find.PNG). Even though admin inputs the correct login credential, the login dialog still remains.
A 401 error was thrown when posting request to EPiServer/Find/api/editorialboosting/searchwithweights/
The OWIN startup set the Bearer Token Authentication, which causes the problem. I believe this is a bug. But any workaround would be appreciated!