Switches of the GS-3xxx series with firmware 4.00 Rel support a port description with a maximum of 16 characters. The LMC supports a port description with a maximum of 47 characters.
When a port description with more than 16 characters is used with firmware 4.00 Rel in the LMC under Device → <Device Name> → Overview, an error message is displayed in the LMC and the configuration cannot be rolled out.
As of firmware 4.00 RU1 the maximum amount of characters in the port description of GS-3xxx series switches has been increased to 47 characters like in the LMC. Therefore the behaviour described above cannot occur anymore with this firmware version.