How to upgrade older firmware from "U" to "UX"
The latest 360v2-series cameras firmware carries “UX“ in its firmware filename, where previously “U“ was used. This change is minor and does not mean much with regards to the functionality of the firmware. However, some older “U” do not allow direct upgrade to the latest “UX“ firmware.
In these cases, an intermediate step must be taken: first upgrade firmware to the nk20210916UX version; after this, the camera will allow the firmware upgrade to the latest version found on the public download pages.
This intermediate firmware version nk20210916UX can be downloaded from here: