So I'm using the iOS Mobile SDK. I had an app working without issue, then changed the Consumer key to that of a different connected app (i.e. changed away from the default sample one) and updated the success URL as well.
Ever since then I've receieved this error when trying to sign in. I've killed all sessions, I've updated and saved that connected app, I've deleted the app, cleaned and rebuilt, and still no joy.
Anyone have any ideas? This message couldn't be any less useful.
Best Answer
After much trial and error. I think this may be due to simple mis-configuration of the Connected App.
Check the Scopes closely. For my trailhead app I needed the api, web, refresh_token scopes. I had omitted one of these. Obviously the scopes required will vary for the app, but at a minimum we need these 3.
Scope parameter docs: https://help.salesforce.com/HTViewHelpDoc?id=remoteaccess_oauth_scopes.htm&language=en_US