Upgrading the Citrix Virtual Delivery Agent (VDA) seems to be more and more a problem than an easy process. I don't understand it anyway why the VDA cannot be pushed by the DDC on request. Meanwhile, we have to fight Citrix and Microsoft to get the VDA installed or upgraded. Here are points you should follow to be successful.

With Internet Explorer 11 and above you must use the group policy Control Panel Settings within the Preferences. In previous versions of Internet Explorer and group policy you could use the Internet Explorer Maintanance but was causing a lot of trouble. The reason why Microsoft completly removed it from group policy. Instead you have to use the preferences and here are some frindly advies on what to look out for.

Time is an important value for authentification and other things and the reason to ensure from the beining it's working in your setup. Deploying Citrix Netscaler in a High Availability (HA) paair is very common, especially when we are talking about the VPX editions. First thing you should ensure is that the time between both Netscaler are in sync.

Let's start with there should be an Option in the Internet Information Service (IIS) application settings to set the default domain and hide the entry. It's really not that hard, so I don unterstand why Citrix isn't doing it.

Here a short description how to permanantly set your domain and then hide the domain filed from the Citrix Director logon page. 

Citrix Receiver... I don't even no where to start with all the issues I had/have and workarounds I have in place to make Receiver at least somewhat useable. The whole thing with Receiver/StoreFront is so "touchie"...anyway, now I just want to let you know something about proxies with Receiver.

Maybe you noticed, maybe not but scrolling in Office (Excel, Word...) doesn't show the content on Windows server 2012R2 with XenDesktop/XenApp 7.x This can be quite annoying and took some time to find out that Citrix is the reason for it!

Citrix XenDesktop/XenApp 7.x is lacking on some features or functions that was in XenApp for many years. Personally I don't understand why Citrix didn't build them in the product from day one XenDesktop 7 was released. Now Citrix is just creating workarounds on customer requests. What I'm talking about you ask?