I'm getting this error with the current version (had it in 0.1.2 as well). Had to revert back to 0.1.1
22.567 Loading mod ItemUpgrades 0.1.3 (data-final-fixes.lua)
22.822 Error Util.cpp:57: Failed to load mod "ItemUpgrades 0.1.3"
ItemUpgrades/data-final-fixes.lua:3: attempt to index field 'lib' (a nil value)