Is the affected group name somehow special? What happens if you do not configure computer filters? Can you alternatively try to install Veyon 4.5.1 and replace libldap-common.dll in the installation directory with https://github.com/veyon/veyon/releases/download/v4.5.1/libldap-common.dll (make sure to stop the Veyon Service and any Veyon-related programs such as Master or Configurator before). It contains a minor improvement which might change the behaviour.
If it does not help, please change the log level to "Debug", stop Veyon Configurator, remove C:\Windows\Temp\VeyonConfigurator.log, start Configurator again and click the List all entries of a location button and enter the name of the affected group/location. Afterwards paste the content of C:\Windows\Temp\VeyonConfigurator.log so we can have a look at the related debug messages.
No it's not a problem To use Veyon with RDP sessions you have to enable multi session mode (https://docs.veyon.io/en/latest/admin/reference.html#refmultisessionmode) and access computers via the corresponding network ports, e.g. add computers with hostname "192.168.....:11101" to access the first RDP session, "192.168.....:11102" for the second RDP session and so on. Make sure to use Veyon 4.5.1 or a newer version. When working with RDP sessions it's recommended to use the NetworkDiscovery add-on which can also scan for sessions and provide them in Veyon Master dynamically.
I may have misinterpreted the question from the original post.
If I understand, the question is what are the steps to block all websites except for one.
To my knowledge there is no native facility within Windows to block websites by name aside from Hosts file entries. Windows Hosts files by current design do not allow for wildcard URI delimiters, so blocking all websites by name would prove a bit impractical.
Since most employees who oversee computer labs do not have management access to their employer’s DNS, DHCP and proxy resources one simple alternative to accomplish the task at hand is to implement an intermediate DNS server. The idea is to intercept and filter DNS lookups.
One such self-hosting DNS server/forwarder is the open source server Technitium.
You will be prompted to set the Technitium admin account password.
The DNS server console will open as a page containing a series of tabs.
Open the Settings tab where you will see the server computer’s name (DNS Server Domain).
Scroll toward the bottom of the page and in the Forwarder section enter your organization’s DNS server IP addresses (usually there are two). The server addresses can be found by entering ipconfig /all at a Windows command prompt.
These entries are needed so that DNS lookups not handled by your Technitium DNS server will be forwarded to your regular DNS servers. Click the Save Settings button and then the Flush Cache button.
Next, open the Blocked Zones tab.
Click the Import button.
In the Blocked Zones window enter *.*to block all websites (note the asterisk delimiter) or any other particular URLs you wish blocked.
Click the blue Import button to close the Import Blocked Zones window.
You can use the blue Block button on the current tab to enter URLs individually.
The Export button downloads a text file containing currently blocked zones.
Use the Browse and Delete buttons to edit blocked entries.
Next, open the Allowed Zones tab.
In the same manner as with Blocked Zones enter and edit those URLs you wish to allow.
Referring to the original question, enter the one allowed URL.
In the final step you will need to change/set the DNS server address(es) at each student or client computer from your organization’s DNS servers to the Technitium DNS server.
At each computer open Network Connections by entering ncpa.cpl from a command prompt.
Right-click the listed Ethernet adapter and select Properties, (assuming IPv4) select Internet Protocol Version 4 (TCP/IPv4) then click the Properties button.
If static DNS entries are present replace those with the IP address of your Veyon master computer or the IP address of the domain/workgroup server from which you are running the Technitium DNS server.
Otherwise, select ‘Use the following DNS server addresses:’ then enter the Veyon master computer IP address (or domain/workgroup server IP address) as the Preferred DNS server entry. Leave the Alternate DNS server entry blank.
Although this would be useful as a temporary solution in the classroom, the best ways are to modify the host file in each computer, or to put any unwanted adresses in the black list of your firewall.
We've kept the default Configurator path even though the redirected H:\Pictures folder would be the more practical. The original Windows 10 default profile folders should still exist so setting the Screenshots path to C:\Users\username\Pictures would save the files locally.
You might try mapping a P: drive directly to the roaming profile share \\<servername>\<fileshare>\<username>.V6\Pictures then set Configurator to use P:\ drive for storing screenshots. No way for me to test here.
Request logins using accounts with blank passwords be allowed as a configurable option.
We use Active Directory to assign generic accounts to particular workstations by MAC address. In this way accounts without passwords are limited to logins at specific sets of computers where security is controlled at the machine level.
Our library uses the limited PATRON account for public catalog and database access and for general browsing of our collection. It would be convenient to log in our public computers en masse using this password-less account.
Students and faculty requiring broader access also have the option to log in using their assigned domain account.
Use the Veyon ‘Run program’ feature for running either a Devcon or PnPUtil script to disable (and enable) the device’s HID-compliant touch screen drivers using the specific HID\VID device instance path(s) and without the need to restart Windows.