Decision tree

Use this guide to quickly narrow down a problem and find the right help article.

Code will not run

1. Is there a red error message in the console?
   • Yes, it mentions a specific line → Check for typos, missing brackets, or undefined variables on that line. See Common issues.
   • Yes, it says "Babel/React is still loading" → Wait a few seconds and click Run again.
   • No error, but nothing happens → Make sure your function is called and that you did not delete starter code the tests rely on.
2. Still stuck? Ask in the Community Forum.

Tests fail

1. Read the failing test message carefully. It usually tells you the expected value.
2. Compare your output with the expected output.
3. Check that your function names and argument order match the instructions.
4. Use the Hint button for targeted clues, or a solution hint when available.

Preview panel is blank

1. Make sure the Preview tab is active, not Console.
2. Confirm the lesson has an html file selected.
3. For React/TypeScript previews, wait for Babel and React to load, then click Run.
4. Check the browser console for JavaScript errors.

I cannot sign in

1. Verify your email and password. Passwords are case-sensitive.
2. If you use GitHub OAuth, make sure you are signed in to the correct GitHub account.
3. Try a different browser or clear cookies for nextdeveloper.com.
4. If you forgot your password, use the Forgot password link on the Auth page.

My progress is missing

1. Progress is tied to your account. Make sure you are signed in with the same email you used before.
2. Lesson progress is not saved while you are signed out. Sign in before you start a lesson to keep your work synced across devices.
3. Free users keep progress across sessions after signing up.

Need more help?

• Read Common issues.
• Post in the Community Forum.
• Email hello@nextdeveloper.com.