• So this is going to sound odd but bare with me. I just pushed Veyon out to over 100 student and staff PCs this past week. We started having issues with Adobe Reader crashing on various machines around the same time. It just says "Adobe Reader has stopped working." Thinking the two events were just coincidence, we ran through Adobe troubleshooting steps like uninstall/reinstall, rolling back to older versions, changing compatibility, etc. After none of those steps worked, we realized the only difference with the machines since Adobe started crashing was installing the Veyon service. So for kicks we uninstalled Veyon and BOOM- Adobe worked. We reinstalled Veyon and BOOM- Adobe started crashing again. Somehow the two are linked and we can't figure out how to resolve this issue. Is there something we can do to remediate this? Like I said we use Adobe and Veyon on numerous machines and this is a headache to say the least. Any ideas on how one program will affect the other? Thanks for any/all help you can provide, because we are stumped.


    Adobe Reader has a built-in security feature called Protected Mode. Protected Mode was enabled during startup by default. So for kicks I uninstalled Veyon (so I could get into Adobe), and in Adobe Reader I went to Edit > Preferences > Security (Enhanced) and unchecked the "Enable Protected Mode on Startup" box. I then installed Veyon and BOOM- Adobe worked. For confirmation sake, I then enabled Protected Mode and BOOM- Adobe crashed.

    We guess Protected Mode won't allow Adobe to run while a VNC client is also running, to ensure someone isn't snooping. We then just ran a GPO that changes that Protected Mode setting in the client registries so we didn't have to screw with any uninstallation/installation of Veyon.

    TL;DR - if you're running Veyon, disable Protected Mode in Adobe so it won't crash


  • Hello
    Would you have the registry key to modify ?? because I think I'm going to have the same problem ...
    Thank you

  • @fred We had to actually create the dProtectedMode registry key then we set up the GPO with the Registry Key Wizard to change the client's registry key to "0" which disabled Protected Mode. More info on the key and key path we found here:


    Hope this helps. Let me know if you have other questions

  • Thank you for the feedback
    I will update the acrobat reader by msi in a few days on my school ...
    and as veyon is already installing, i will be doing some testing with this registry key.

  • Thank you, i have the same problem. But in my school, we have a lot of virtualized applications and they crash when Veyon Master's running. I don't know what to do.

  • good evening
    I encountered a crash of acrobat reader dc when the 32bits version of veyon is installed on a windows 7 64 bits ... but
      only when a user is logged in, if it is an administrator no worries ...
    I installed the 64bits version of veyon on the same computer, and acrobat reader DC works whatever the logged in user