Help · When something is wrong
What the common failures mean, in plain words, and what to do about each one.
A failed build means we could not turn your code into something runnable. Your previous version, if you had one, is still online and serving — a failed build never takes down what was already working.
Open the app and read the build log. The real error is usually in the last few lines.
"Cannot find module" or "No module named" — your code uses something that is not in your dependency list. Add it to package.json or requirements.txt and deploy again. If an assistant wrote the code, telling it "this failed because X is missing" usually fixes it in one go.
"We could not work out how to run this" — the files do not look like anything we recognise. Usually the zip contains a folder containing your project, rather than the project itself. Zip the contents, not the parent folder.
A syntax error — there is a typo in the code. The log gives you the file and line number.
"Out of build minutes" — you have used the month's build allowance. See what the free plan includes.
It just stops with no clear error — occasionally a build runs out of memory. If the project is large, this is the likely cause; get in touch and we will look at it with you.
That is a fair reaction, and it is often our fault for showing you a message written for programmers. Paste the last few lines into a support ticket and we will tell you what it means and what to change.
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