Seamless Windows applications can not be ran by default. On Windows Server 2012 you need to add a collection and explicitly allow seamlessrdpshell in order to be able to use tl-run-winapp-seamless.
We could investigate the possibilities of doing this automatically in the WTS-tools installation.
See bug 5887
This might be overridden in an Active Directory environment which could prevent an automated solution. Perhaps documentation is the answer to this issue.
*** Bug 7036 has been marked as a duplicate of this bug. ***
We have decided that updating the documentation is enough for now.
For doing this automatically I created bug 7066.
Documentation has been updated.
Really nice work done on the documentation, +3.