Just something we ran into this week. We have a customer with a Windows 2012 R2 Remote Desktop (RDS) environment that still had some users that use Windows 7 client computers to connect.
They were able to login to Remote Desktop Web Access successfully, but when they tried to launch a Publised App, they kept getting a Windows Security pop-up asking for credentials (Username and password) :
At first, we assumed it had to be Windows 7 client related, as this OS is pretty old and Windows 10 clients didn’t have issues.
However, in the end, it was resolved by changing the redirect settings on the Default Web Site that RD Web Access is installed on so that everything get’s redirected to /RDWeb but not sub directories.
You can find this in Internet Information Services under the Default WebSite – HTTP Redirect.
Make sure that the checkbox:
Only redirect requests to content in this directory (not subdirectories) is selected.
After adjusting that setting and selecting apply, Windows 7 clients could successfully launch Published Applications.