I cannot decide if it is more infuriating to Google a problem and get no results or to get a single result that is not helpful in any way.
I came across this problem at a customer recently and the only thing the search giant could offer me was a singular thread on a forum somewhere that basically said “We had this problem. Then it went away and we can’t reproduce it. Nevermind I guess.”
Occasionally, a user would attempt to retrieve their XenDesktop session and would be met with “Virtual Driver Error” instead. This would disrupt the connection and the user would be unable to bring up their session. If they waited a sufficient amount of time and tried again, it worked. Rarely, trying again immediately worked as well. I was ultimately able to make the problem 100% reproducible. The customer had a mixed environment of these Wyse zero clients and PCs with Citrix Receiver agents (Enterprise v3.1) installed. If you spun up a new session from the PC, then tried to roam it to the Xenith, you would get the error. If you spun the session up on the Xenith, moved it to the PC and back, you would be fine.
I will spare you the troubleshooting steps that resulted in the following conclusion, but the fix was to change the color depth on the PCs from 32bit to 16bit (for Win7: Right click on desktop > Screen Resolution > Advanced Settings > Monitor tab). Once this fix was applied, we never saw the problem again. Reverting back immediately reintroduced it. To that end, if you have stumbled onto this post and elect to use this fix, we also found that the color depth setting did not get stored as part of the image for the PCs, and imaged machines had to be touched manually to apply the fix after the fact. Something to keep an eye on when deploying this.
If this, for whatever reason, is not an acceptable fix, I would encourage you to focus your troubleshooting on your display settings, either in terms of drivers installed locally or in your master image. This is as far as I went with this problem, but hopefully it’s a step in the right direction for someone more persistent. I was going to post it as a reply to the unhelpful thread (found here), but I didn’t feel like creating an account to do so.
If you find a better fix, leave a comment and let me know.