The Nokia 6700 Classic must have the correct software version to run Nokia Messaging.  First, the software version on the device must be identified.  It is possible to identify via a key sequence entered at the idle screen to identify the software version included in a Nokia 6700 Classic handset.  The sequence is *#0000#. 

The software version will now appear.  If the software version is either 06.95, 07.60, or 07.90, you will have to upgrade your 6700 via a Nokia Service Center or through the Nokia Software Updater to run Nokia Messaging.