When a disk is connected inside the NoMachine session and a file is opened from that disk with a program having the auto-save feature enabled (e.g. LibreOffice Calc or Microsoft Excel), the same disk cannot be connected again at the next session startup.

This happens only if the file stays open when the NoMachine session is terminated or the disk is disconnected. The NoMachine mount point is deleted as expected, but the program's autosave function creates a mount point and saves the open file within, making no longer possible to mount the disk  - with the same mount point -  when the NoMachine session is started again.

This problem occurs with disks connected from locale to remote and vice-versa, in NoMachine virtual desktops and physical display sessions.

There are two possible alternative workarounds.

First workaround
Remove the mount point that was created by the program with the auto-save feature enabled.

To do that, run use the command line (e.g. rm -rf <mountpoint>) or right mouse click on mount point icon and remove this directory.

The mount directory is by default on the desktop unless user has changed the path via the NoMachine user interface or modified the node configuration by setting the DiskSharingPrivateBasePath key.

Second workaround
Change the name of the mount point in the NoMachine user interface before mounting the same disk, so a different mount point will created.