GuidesPreview
Recover when a build is rejected or fails
Preview validates generated output before it renders it, and refuses output that fails. What each rejection means and which of Retry, Simplify or Restore to use.
Draft — not yet walked in the live product
All 6 steps below were written by reading the Keenoble source rather than by performing them, and each unwalked one is tagged [UNVERIFIED]. Reading a component tells you what a control is labelled; it does not prove the control is reachable, that the order is right, or that the result is what the text says. Until a reviewer has walked every step, this page is excluded from the sitemap, marked noindex, and publishes no structured data.
Before you start
- A build that ended in a banner rather than a page.
Steps
Read which banner you got. “Build stream failed” means the connection to the model broke. “Build output rejected” means output arrived and was checked and refused. [Unverified]
On a rejection, read the line under the heading. It names the actual reason — the model returned planning text instead of HTML, the page has no visible text, the output is missing a required tag, the CSS hides the whole page, and so on. [Unverified]
The banner also prints how large the rejected output was and which class of check refused it.
Click “Retry” to run the same prompt again. Use this when the failure looks incidental. [Unverified]
Click “Simplify prompt” when the same rejection keeps happening. It re-sends a reduced version of your request. [Unverified]
After the same rejection fires twice inside a minute, the banner says so directly and points you at Simplify.
Click “Restore previous” to put the last working version back in the preview. This is available whenever there is a previous version to go back to. [Unverified]
Dismiss the banner with the ✕ if you would rather change the prompt yourself and send again. [Unverified]
The preview crash banner
Separately from a rejection, the preview itself can fail to render. That shows as “Preview couldn't render — your previous site is still saved. Send a message to try again.”
The wording is exact on purpose: a failed render never overwrites your saved build.
Why a build gets refused at all
Rendering whatever the model returned would sometimes mean showing you a blank page, an apology, or a server error page dressed up as a result. Preview checks the output first and tells you what was wrong with it, which is slower to read and more useful than a silent blank screen.
Next
Having problems with the platform? Contact us at support@keenlabs.pro. If a step here does not match what Keenoble does, the step is the bug — send it to the same address. All the guides are at /guides; shorter answers are on the FAQ.