Yesterday customer had a problem with Direct Access and Citrix. The situation was …

Direct Access worked just fine, but applications published thru XenApp didn’t open. The problem was that Citrix XenApp didn’t send Fully Qualified Domain Name (FQDN) response to the Direct Access clients.

https://support.citrix.com/article/CTX135250

https://support.citrix.com/article/CTX128436

When that was fixed there was a problem with Netscaler Access Gateway. It wasn’t configured to use DNS-resolution and this option is Disabled by default, so You probably have to enable it.

https://support.citrix.com/article/CTX109556

And this was it. Published application are alive again 🙂