Migrating from SonicWall Firewall Gen 6 to Gen 7
When moving from a SonicWall Firewall Gen 6 to a Gen 7, it is recommended that the Migration Tool is used to convert the settings. It is possible to simply import the old settings file (.exp) from the Gen 6 appliance into the new Gen 7, but this is not the recommended method by SonicWall, and if problems occur later, the SonicWall Support team may request you follow the migration tool procedure before continuing. As part of the support process they will ask for a TSR (Tech Support Report) to be uploaded, and this shows the method of settings transfer and it can tell how it was performed.
There is a KB article outlining the compatibility and processes which can be found here.
You may find that some migrations aren't supported/listed, so you will need to reach out to the SonicWall Support team to assist. They can convert the file for you until the automatic migration tool lists your models. This is currently the case when moving from a NSa model Gen 6, and going to a TZ model Gen 7 e.g. NSa 2650 to TZ670.