How to fix `undefined has no properties`

Firefox throws 'undefined has no properties' when attempting to destructure null or undefined values. This commonly occurs with API responses returning null, missing function arguments, or async data not yet loaded in components. Fix by adding fallback objects using nullish coalescing (??), setting default function parameters, validating data before destructuring, implementing loading state checks in React/Vue/Angular, or using optional chaining. TypeScript can prevent these errors at compile time by enforcing type checks.