This is using Metabase 53.2 but I had the same problem with 52.x.
I have a simple website running on a customer's server to display a list of Crystal Reports the user can view.
It's using IIS and Windows Authentication (HTTP 401 Challenge).
Before the list is displayed, the user is prompted for their user name and password.
I'd like to embed this in Metabase using an IFRAME card so that all their analytics stuff is in one place.
I've added the domain to the list of allowed domains but it's still saying 'There was a problem rendering this content.'
In edit mode, I get:
I assume this is something to do with the security.
Any thoughts on a workaround?