OAuth2 authentication fails with a Cross-Origin Resource Sharing (CORS) service error when accessing Portal for ArcGIS 10.3.1 hosted on federated ArcGIS 10.3.1 for Server, which has Integrated Windows Authentication (IWA) security.
Bug ID Number
August 4, 2015
December 1, 2020
The bug has been fixed. See the Version Fixed and Additional Information, if applicable, for more information.