Access denied when shadowing Remote Desktop with dual monitors

Recently, a customer said they were no longer able to shadow remote desktop sessions for some new thin clients that were installed.  The error message was "Access is Denied".  It turns out that these new thin clients were dual monitor setups.

According to  https://support.microsoft.com/en-us/kb/2484290 , this is normal behavior when trying to shadow a multiple monitor session.

Networking Remote Desktop