This problem has been encountered when upgrading NoMachine from v. 5.2.21 to v. 6.5.6 and NoMachine Enterprise Client from v. 6.2.4 to v. 6.6.8. After the upgrade, USB forwarding stopped to work in NoMachine sessions and  Error Code 45 was raised on USB host controllers in device manager.

This issue is triggered by the fact that NoMachine USB drivers are not updated properly to the new drivers version provided since v. 6.3.
 

As a possible workaround: 

- uninstall the old NoMachine version, e.g. v. 5.2.2.

- Reboot the Windows machine to completely unistall the old USB drivers.

- Then make a fresh new install of the last version of NoMachine, e.g. v. 6.6.8 .