Citrix XenApp 7.13 - Set default programs

I have recently set up a new XenApp 7.13 farm for a client.

The problem: users were prompted to choose a default app every time they tried to open IE/PDF files.

The solution:
To set the associations, use the following steps:

On the XenApp server running Windows Server 2012+, login as administrator and set all the default programs. Even if you already have a default program assigned, you will have to re-assign it.

Run the following command: 

Dism /Online /Export-DefaultAppAssociations:\\Server\Share\AppAssoc.xml

Verify the XML file exists, as shown in Figure 2.

Open the Group Policy Management Console (GPMC) and create a new group policy OR you can modify an existing, if you have one.

Navigate to Computer Configuration\Policies\Administrative Templates\Windows Components\File Explorer\Set a default associations configuration file as shown in Figure 5.

Enable the Set a default associations configuration file policy setting and enter the path to the XML file.

Click OK, exit the group policy editor, and link the new policy to the appropriate Organizational Unit for your XenApp servers that use Windows Server 2012+. After the group policy refresh interval or restarting the server(s), the new group policy setting will be applied and application associations will now work.

The main problem with this new method is that the XML file is static. If any new applications (with file type associations) are installed, the XML file will need to be recreated.

I got the steps from this site, but added one more step at the very beginning: Carl Webster - Citrix