Rewritten
You're calling `.map()` on something that is `undefined` rather than an array. Usually this means the data you expected hasn't loaded yet (e.g. an API response before it arrives), a variable name is misspelled, or a function returned nothing where you expected a list. Check that the value exists — often by guarding with a default like `(items || []).map(...)` or waiting for the data before rendering.
About this tool
Error messages are written for the machine's benefit, not yours, and a stack trace can bury the actual problem under framework noise. This tool takes a raw error or trace and explains, in plain language, what it most likely means and the common reasons it shows up. It won't fix your code for you, but it points you at the likely culprit faster than parsing the jargon yourself — useful when you hit an unfamiliar error and want a direction to investigate before diving into a search.
Frequently asked questions
Will it tell me exactly how to fix my bug?+
It explains the likely meaning and common causes to point you in the right direction, but it can't see your full codebase, so the specific fix is still yours to apply.
Can I paste a full stack trace?+
Yes — pasting the whole trace helps, since the most useful information is often a few lines into it rather than the top line.
Does it work for any language or framework?+
Yes — it handles errors from common languages and frameworks and explains the general meaning even for less familiar ones.