Struggling with demo-ing my screen

[matthains]

I can get a demo screen (my screen) to show up on the users' computers screens. But the moment I right-click or move anything or launch an application, the screen goes black. The Windows 10 error log reads:

Faulting application name: veyon-server.exe, version: 4.7.3.0, time stamp: 0x00000000
Faulting module name: ntdll.dll, version: 10.0.19041.1682, time stamp: 0x7b5414ec
Exception code: 0xc0000374
Fault offset: 0x00000000000ff249
Faulting process id: 0x1874
Faulting application start time: 0x01d8904af7275a92
Faulting application path: C:\Program Files\Veyon\veyon-server.exe
Faulting module path: C:\Windows\SYSTEM32\ntdll.dll
Report Id: 7fc3079e-909b-4e66-ac7e-7383420ba700

Have followed all the various bits of advice online but still cannot get demo mode working correctly.

[tobydox]

For some reason the (Ultra)VNC server inside veyon-server seems to crash when accessing/processing your display. It's hard to debug that but you could try playing with the VNC server options in the Service configuration tab in Veyon Configurator. For doing so switch to the advanced view in the window menu and select Builtin UltraVNC in the VNC server drop down menu. May be changing the options Enable Desktop Duplication Engine on Windows 8 and newer or Enable capturing of layered (semi-transparent) windows have a (positive) impact on the behaviour. Also make sure to update to the latest version of Veyon (4.7.4).