Fixing preview errors
What to do when the preview shows an error, stays blank or won't load.
"This version hit an error"
When your project crashes, an error panel appears over the preview with the message. Press Fix with AI: it sends the exact error to the chat, and the next version fixes it. This handles most problems in one step.
The preview stays on "Starting preview…"
- Web Apps: after 20 seconds you'll see an explanation and a Try again button. The first preview downloads a few megabytes of tools (React, Tailwind and a code compiler) from appfully.dev, so a slow connection, a VPN or a content blocker can hold it up. Try again, or pause your blocker for appfully.dev.
- Apps: Expo's player can take 10–20 seconds the first time. Press Reload if it's longer.
"The operation is insecure" or "SecurityError"
These came from browser features that are blocked inside the safe preview sandbox. Appfully now provides safe stand-ins for storage, page URLs, IndexedDB and service workers, so you shouldn't see them. If you still do, press Fix with AI, or tell us via Support with the project link.
A blank preview with no error
Usually the app renders nothing for its starting state (for example an empty list with no empty-state message). Ask: "Show sample data on first load and an empty state when there's nothing."
A link or button "does nothing"
If a link points to a page that doesn't exist yet, the preview shows a short note instead of leaving. Ask the AI to build that page or wire the button up.
Still stuck?
See Troubleshooting, or contact Support.