Unexpected Application Error! Cannot read properties of undefined (reading 'length')

[sajadhn1988]

Unexpected Application Error!
Cannot read properties of undefined (reading 'length')
TypeError: Cannot read properties of undefined (reading 'length')
at Header (http://localhost:3000/static/js/bundle.js:680:51)
at renderWithHooks (http://localhost:3000/static/js/bundle.js:52269:22)
at mountIndeterminateComponent (http://localhost:3000/static/js/bundle.js:55555:17)
at beginWork (http://localhost:3000/static/js/bundle.js:56851:20)
at beginWork$1 (http://localhost:3000/static/js/bundle.js:61814:18)
at performUnitOfWork (http://localhost:3000/static/js/bundle.js:61083:16)
at workLoopSync (http://localhost:3000/static/js/bundle.js:61006:9)
at renderRootSync (http://localhost:3000/static/js/bundle.js:60979:11)
at recoverFromConcurrentError (http://localhost:3000/static/js/bundle.js:60471:24)
at performConcurrentWorkOnRoot (http://localhost:3000/static/js/bundle.js:60383:26)
💿 Hey developer 👋

You can provide a way better UX than this when your app throws errors by providing your own ErrorBoundary or errorElement prop on your route.

[sajadhn1988]

Unexpected Application Error! Cannot read properties of undefined (reading 'length') TypeError: Cannot read properties of undefined (reading 'length') at Header (http://localhost:3000/static/js/bundle.js:680:51) at renderWithHooks (http://localhost:3000/static/js/bundle.js:52269:22) at mountIndeterminateComponent (http://localhost:3000/static/js/bundle.js:55555:17) at beginWork (http://localhost:3000/static/js/bundle.js:56851:20) at beginWork$1 (http://localhost:3000/static/js/bundle.js:61814:18) at performUnitOfWork (http://localhost:3000/static/js/bundle.js:61083:16) at workLoopSync (http://localhost:3000/static/js/bundle.js:61006:9) at renderRootSync (http://localhost:3000/static/js/bundle.js:60979:11) at recoverFromConcurrentError (http://localhost:3000/static/js/bundle.js:60471:24) at performConcurrentWorkOnRoot (http://localhost:3000/static/js/bundle.js:60383:26) 💿 Hey developer 👋

You can provide a way better UX than this when your app throws errors by providing your own ErrorBoundary or errorElement prop on your route.

consider the following: cartItems && cartItems.length === 0

[bushblade]

Hi @sajadhn1988
Are you a student of Brads? If so can you post in the course Q&A or over on Brads Discord server please, make sure to include a link to your projects repository.
If you're not a student then can you tell me if this is using the repository code or your own project?

[bushblade]

Closing due to lack of information and not able to reproduce using repository code.