cordova-cli@5.4.0 is not updating the metadata information on the cordova_plugin.js file. Because of this ng-cordova Oauth plugin stopped working(Could not find inappbrowser). ng-cordova Oauth plugin uses this metadata information in the cordova_plugin.js file to check whether the inAppBrowser plugin is installed or not. I installed 5.3.3 to get rid of this issue.
This has been reported as a bug. Have you tried removing adding back your plugins? That's been suggested as a work around.