I'm running this mod along with K2-SE, and after updating I was told there was a conflict with "Paracelsin Krastorio Compatibility+", linked below. Disabling that has given me the same error as the OP.
https://mods.factorio.com/mod/paracelsin-krastorio-compatibility-plus
I had a this error when I disabled "Realistic weapons" in the settings (K2-SE). My workaround was to load only K2-SE and enable the option, then restart with all mods active again.
I'd like to try this solution but my modlist is like 100 mods long and it would be a huge PITA to disable and then re-enable all of them.