I am trying to set the redirect\_uri for the facebook login with Asp.Net Identity. However, the `GetExternalLogin` REST method in the `AccountController` is only triggered if the redirect\_uri is '/'. If I add anything else it does not trigger `GetExternalLogin`, the browser only shows *error: invalid\_request*. 

However the url contains the redirected parameter as it should e.g. if I add the redirect\_uri as `http://localhost:25432/testing`

the response URL looks like this:

```
http://localhost:25432/api/Account/ExternalLogin?provider=Facebook&response_type=token&client_id=self&redirect_uri=http%3A%2F%2Flocalhost%3A25432%2Ftesting&state=0NctHHGq_aiazEurHYbvJT8hDgl0GJ_GGSdFfq2z5SA1

```

and the browser window shows: `error: invalid_request`   

Any idea why this works only when redirecting to '/' but not to any other url´s?