Is it possible to use Office Web Apps Server 2013 to give external SharePoint Foundation 2013 clients access to Office documents in a View only capacity?
Does FBA work with Office Web Apps or would external users have to at least have a Windows CAL in AD if we are just using SharePoint Foundation?
Office Web Apps can be used only by SharePoint 2013 web applications that use claims-based authentication.
There is a known issue when using Office Web App in the extended zone with FBA, but not the default zone. Please configure FBA authentication in the Default zone in case of that.
Hope it helps.
Regards,
Rebecca Tu
TechNet Community Support
Marked as answer bystar.warsSunday, May 4, 2014 1:57 PM