SP 2016 on premise extranet - Opening document asks for login, does not open document

Question

We are building an extranet in a dedicated on-premise environment. We want documents to default to opening in the native application. Opening in the web app is not considered an acceptable user experience.

External users are asked to enter credentials in the native application, but the document never opens. External users log in to the SharePoint site collection with credentials from our AD.

Current hypothesis is that SharePoint is providing credentials from our AD, while the user's office application is expecting their internal credentials.

Is there a solution for this?

Answer 1

Further investigation with our IT team revealed that the problem is we do not use a Microsoft product for identity management. We use an IBM product. So we are having the problem even for internal users. We're now exploring implementing ADFS for identity management for the extranet.