For GOS 5.0 and GOS 4.3 new patch levels are available:
These releases unlock the migration to and support the operation of GOS 5.0 for the older GSM 6400 & 5300 ENTERPRISE models.
For further information on GOS 5 please see the announcement at:
Both patch levels also include several bug fixes and improvements for the respective GOS versions.
In total GOS 5.0.5 covers 8 improvements and GOS 4.3.16 covers 2 improvements.