Until this update, there was a flaw (only discoverd in the past year) with how the .sknr format was searlized via pickle : it would physically pickle the Numpy ndarray's. The downside is, if userA saved out using numpy 1.x, and userB tried to import using numpy 2.x : userB would not be able to load userA's sknr files, based on binary incomabilities / API changes when trying to deseralize the pickled ndarray data.
v1.5.1 addresses this, by converting the ndarray data to standard builtin types for pickle searlization. Meaning, the version of numpy the user has installed will no longer impact the saving/loading of the sknr format.
However, this only addresses the issue with new sknr files saved in v1.5.1 or newer: Old files will still have the same limitation of numpy major version incompability. If you find yourself in this situation, the 'fix' is to 'simply' re-export the existing sknr data on a machine that has the 'correct' version of numpy installed: Clearly, this could be batched if needed, but annoying. See the notes in the v1.3.1 release on this.
But live and learn!