I happened upon a pretty interesting issue. At first the support ticket was pretty bog standard. Mapped Network Drives not appearing in Citrix session. That could be for any number of reasons and is usually something pretty straight forward.
We recently deployed RemotePC and Shared Desktops running on XenApp 7.15 CU3 to quite a few people. We started getting a flurry of tickets about missing Mapped Network Drives. One of the users explained to me that the drives appear fine in a Citrix session when launched on a VMware Horizon virtual desktop and even appear fine when launching from the same workstation being accessed through RemotePC....so on the workstation in the office it works perfectly but when removing into the workstation through RemotePC it does not.
This explanation made me immediately wonder if the issue was due to a double hop. I told the user as much but wanted to confirm. I was able to re-create the exact same behavior for myself and confirmed all the other users were using RemotePC. The only one not was using a Shared Desktop, which really made me think it was a double hop issue. HDX inception!
I figured out what was wrong but all my Googling turned up results for XenApp 6.5. I decided to try out the Citrix support chat to get an answer for 7.x.
The following registry setting was required:
Set to True
Unfortunately, this setting is not available in the Receiver Group Policy Template. When you change this registry value, you'll have to exit Receiver and re-open before it will apply. You can find more info on the setting HERE.