DebugSmith field guides
Practical fixes for the failures that waste a day.
These short guides explain what to inspect first, what a safe fix looks like, and how to prove the original failure is gone. They are free to use and updated when the underlying platform guidance changes.
JAVASCRIPT
Cannot read properties of undefined
Find the missing boundary value instead of hiding the error with a broad rewrite.
Read the guide → CHROME EXTENSIONSWhen an MV3 service worker goes quiet
Design for restarts, persist state safely, and inspect the worker that actually shipped.
Read the guide → VERCELPreview works, production fails
Compare the deployment, environment, hostname, and runtime evidence in the right order.
Read the guide →Need a diagnosis?
Bring the evidence to the Repair Lab.
Paste the exact error, a public URL, or the smallest relevant code block. Basic checks run without an account and return a downloadable packet.
Start a free repair scan