Preview Loading Problems
The embedded preview can show progress, a ready state, or an error. A ready state means the preview reported ready; it does not confirm that the app works as intended.
| What you see | What it tells you |
|---|---|
| “Building your app” with “Bundling code,” “Starting preview,” and “Compiling styles” | These are progress cues, not confirmation that the app has loaded successfully. |
| A build error | The preview displays the error text. Read it for the reported problem. |
| An unavailable-package error | The message says the app imports packages the preview cannot use and advises using packages available in the preview. |
| “Preview app failed to load: a module import could not be fetched” | The message identifies a network error or an unavailable package as possible causes. Check network availability and whether the package is available in the preview. |
| A message that the preview did not report ready or error within about 60 seconds | About 60 seconds after the build cycle starts, a one-time check reports a timeout only if the preview is still running. If it is not running then, no later timeout is reported; this is not an overall deadline for initial loading. |
[!NOTE] “Try to fix” is not guaranteed to appear for every error. The 60-second timeout disables it; rely on a repair action only if the button is visible.