Lesson 8 of 8
Troubleshooting and what's next
Common problems, quick fixes, and where to go from here.
When things go wrong
Most setup problems fall into one of five categories. Find the one that matches your situation, paste the prompt into Claude Code (or claude.ai if Claude Code won't start), and let Claude diagnose and fix it.
"command not found" after setup
I am a non-technical Mac user. I ran a setup process and was told everything installed correctly, but when I try to run a command I get "command not found". Please diagnose why my terminal can't find the command and fix it. Explain every step in plain English before you do anything.
Homebrew permission errors
I am a non-technical Mac user. I am getting a permission error when trying to use Homebrew — it says something about not having write access to a directory. Please diagnose this and fix it safely. Explain every step in plain English before running anything, and do not delete or overwrite any of my files without asking me first.
Node or npm version problems
I am a non-technical Mac user. I am having a problem with my Node.js installation. Either it's the wrong version, I have multiple versions installed, or npm commands aren't working as expected. Please diagnose the issue and fix it. Explain every step in plain English.
"I closed Terminal and now nothing works"
I am a non-technical Mac user. I closed Terminal and when I re-opened it, commands that worked before (like brew, node, or claude) are now showing "command not found". Please diagnose what happened to my PATH settings and restore them. Explain what you are doing and why.
App won't start
I am a non-technical Mac user. I built an app using Claude Code and it ran fine before, but now it won't start. I am getting an error in Terminal when I try to run the development server. Please read the error message, diagnose the cause, and fix it. Explain everything in plain English.
What to learn next
Once you've built something with this course, here are the natural next steps.
Claude Desktop — A chat version of Claude that accepts screenshots. Drag a screenshot of your app into the chat and say "make this look more professional." Ideal for visual iteration. Download at claude.ai/download.
Cursor IDE — A code editor built for AI-assisted development. If you want to see the code Claude is writing and approve changes line by line, Cursor gives you that visibility. Download at cursor.com.
Vercel — Publishes your app to a live URL in one click. Connect your GitHub account at vercel.com, import your project, and every time you save your work it redeploys automatically. Free for personal projects.
GitHub — Cloud storage for your code with full version history. Every commit is a checkpoint you can return to. Create an account at github.com.
Reference: Claude Code shortcuts
| Command | What it does |
|---------|--------------|
| /model opus | Switch to Claude's most capable model (use for planning) |
| /model sonnet | Switch to the fast model (use for writing code) |
| /effort high | Maximum reasoning effort |
| Shift + Tab | Toggle Plan Mode |
| /exit | Exit Claude Code |
| Ctrl + C | Cancel the current operation |
Reference: Terminal basics
| Command | What it does |
|---------|--------------|
| pwd | Show what folder you're currently in |
| ls | List files in the current folder |
| cd folder-name | Move into a folder |
| cd .. | Go up one folder level |
| mkdir folder-name | Create a new folder |
| clear | Clear the screen |
| Ctrl + C | Stop a running process |
| Up arrow | Recall your previous command |
Still stuck?
Email hello@plainbuilt.co with a description of the problem and a screenshot if you have one. I'll reply within one business day.
If you'd like hands-on help with your specific project, book a 1:1 coaching session.