Lovable build errors, fixed without burning credits
Last updated
Symptom
After a request, the preview stops working and an error message appears where the app should be. It often has technical words, a file name or a line number.
Cause
To show your app, the tool has to turn the code into something the browser can open. That step is called the build. A build error means the code has a problem that stops that from happening, so there’s nothing to show.
The most common causes are a piece of code the AI referenced but never created, a typo in the code, or a change in one part of the app that broke another part that depended on it. Almost always, the problem comes from the last request.
It isn’t your fault, and you don’t need to understand the message. What helps the AI is the full text of the error and knowing what you asked for right before it appeared. If the AI says it fixed it and the error is still there, see The AI says it fixed it, but the error is still there.
Prompt to paste
Copy the text below, replace what’s in brackets and send it in the chat of the tool you’re using.
The app stopped working after my last request: [what you asked for].
This is the full error message:
[paste the whole message]
Before changing anything, explain in plain English what the error means and which part of the app it comes from. Then fix only that error, without changing anything else, and tell me how to check that it worked.How not to burn credits
- Paste the full error message and your last request in a single message. Each message you send uses credits, and short messages like "still broken" give the AI little to work with.
- Ask what the error means before letting the AI change code. In Lovable, Plan Mode costs 1 credit per message, while in the default mode the cost depends on how complex the task is.
- After each attempt, check what it cost in the message history, through the three-dot menu.
- Stop after two or three failed attempts. Go back to the last version that worked and ask for the change again, in smaller steps.
- On the free plan you get 5 build credits a day, up to 30 a month, and daily credits don't roll over. If you run out, write your next request calmly while you wait, instead of sending rushed attempts later.
How Lovable counts credits, and what the free plan includes: Lovable credits explained.
Frequently asked questions
Is my project lost after a build error?
Usually not. The error affects the latest version of the code, and the tool keeps a version history, so you can go back to an earlier point that worked.
Do I need to understand the error message?
No. Copy it in full, exactly as it appears, and send it to the AI with what you asked last. The AI is the one that needs to understand it.
How do I know how many credits a fix used?
Lovable shows the cost of each message in the message history, through the three-dot menu.
Why does the same error keep coming back?
The AI sometimes repeats the same reasoning and the same fix. Tell it the problem is still there and ask for other possible causes before a new attempt.