Hi,
If there are no devices visible it means that USB forwarding is disabled at least on one machine.
Can you please do the following:
1. Start session, go to USB devices forwarding tab, forward flash drive, wait 1 minute.
2. Collect and send Windows client-side logs as described here https://www.nomachine.com/DT10O00163#2.3
3. Collect and send Linux server-side logs as described here https://www.nomachine.com/DT10O00163#1.1
4. Send logs from Windows part as described here: https://www.nomachine.com/AR10K00697
5. Run in Linux terminal following command and copy here it’s output.
lsmod | grep nxusb
Please perform all these actions during a launched session and before devices forwarding restart both machines.
They can be sent directly to forum[at]nomachine[dot]com making sure you use the topic title as the subject of your email.