Answers for "cannot convert undefined or null to object"

cannot convert undefined or null to object

Object.keys(priorVal || {})

TypeError: Cannot convert undefined or null to object at Function.values (<anonymous>) in solidity

I had this issue when compiling using my global truffle module. i switched to npx truffle compile after installing it as a dev dependency. The global module was v5.0.5 and the local module was v5.2.6 . so you might want to check your compiler version.