UAC causes "resolution not supported" error on zero client

[nappyrat]

VMWare View 5.1

Samsung NC240M zero client with second SyncMaster SA450 monitor attached.  Latest firmware from teradici

Dedicated Windows 7 VM

I have a problem that occasionally, i'd say 1 out of 3 times, when i do something that causes UAC to kick in, my screen flashes for a second, the yellow UAC window comes up with the "Do you want to allow this program to make changes etc..." message, and when I hit yes my screen will go dark with a message "Resolution Not Supported".  I'm still connected to the vm, as I can still hear audio.  Resetting the zero client fixes it and I'm right  back into my vm like nothing happened. 

Anybody have an idea what could cause this and how I might fix it, other than the obvious disable UAC?

[adamroland]

Try add more Video memory under name_of_VM Edit Settings ... \ Hardware \ Video Card \ Total video memory.

[padesjar]

Have you by any chance found a resolution to this? I've started experiencing this issue as well and the zero client doesn't matter. I have your Samsung, and it happens on an LG, as well as Wyse and Cisco devices. Did you try the suggestion, if so any difference?

[nappyrat]

No, I never got to the bottom of it but as we're still in a testing phase I havn't pursued it too hard. I did open a case with teradici who has some of the best support engineers i've ever dealt with.  they had a few suggestions that I tried but nothing worked.  Im already maxed out on video memory.  they suggested oepning a case with vmware and i probbly will at some point, but it's good to know i'm not alone!

[padesjar]

Increasing the video RAM helped with performance across multi monitors. Regardless of the calculator and recommendations, we've had to bump it up for smoother affect with windows between monitors. Our users are very spoiled.

This error can occur when given the UAC prompt randomly much like you describe, unfortunately we are seeing it in another case. So far recreating it pretty consistently when the screen goes blank, bringing the screen back up, and the logging into the locked workstation. After about 10 seconds or so, you hear the hardware change sound from windows and then the overlay suddenly appears. Resetting the zero client and reconnecting resolves the issue of course. But, every time the user comes back to the blank screen and log in is way too often to let it pass unfortunately.

[Mickelonis]

I have this issue as well. We run only P20 zero clients.

Issue seems to only happen on dual monitor setups. For me however, UAC prompts do not cause the issue. We only see it when a user is resuming from a locked session.

-Pete

[TomMar]

I have this exact same issue but have not been able to narrow down the cause.  It only happens on two desktops, mine and another person in IT.  We have other desktops that use the same base image, same pool etc. however they have not experianced this issue yet.  We do not have UAC enabled and have 128mb of video ram on each desktop.  Both of ours that show this issue are dual monitors.  I've tried an EVGA PD02, Samsung, Wyse P20 and Wyse P25 and they will all cause this issue.

[padesjar]

Well, we've been able to figure out a work around. It seems it's an issue that VMware will try to resolve in the next release.

The work around is disabling sleep/power save for the monitor. If you set it to never put the display to sleep, then it will not exhibit this behavior. I was able to recreate it over and over. Once we turned off sleep for the monitor for the few people affected, we have not had the issue anymore.

[nappyrat]

makes sense not sure why i didn't think of that. great find!