Running a session on NX Client for Windows can fail because NX Client 3.x relies on 8.3  name creation (or short filename or SFN) to work correctly. If support for short file names and directories is disabled, users will be unable to start a NX
session. This is because NX Client cannot correctly retrieve the path to the nx directory placed in the user's home.

The suggested workaround is to ensure that support for 8.3 name creation is not disabled.

More information about disabling 8.3 name creation is available on the Microsoft website: http://support.microsoft.com/kb/121007/en-us

A definitive solution for NoMachine NX users is to adopt NX Player 4 or later which does not depend on short filenames and directories.