The update of a firewall from an SNS version 3.10.x and upwards to an SNS version 4.0.x must not be performed and is not supported.
Details are available in Recommendations section.
It contains information that you must read before updating SNS to version 4.0.2.
Watch the video to find out what's new in version 4:
This document is not exhaustive and more fixes may have been included in this version.
In the documentation, Stormshield Network Security is referred to in its short form: SNS, and the Stormshield Management Center in the form SMC.