Common errors

In the builder

"This sandbox is not running. Start it from the builder." The preview URL was opened while the sandbox is stopped (idle stop after 30 minutes, or you stopped it). Click Run preview.

"Preview not found." The URL doesn't belong to a project on this account. Check you're signed in as the right user.

"The sandbox stopped responding. Try restarting it." The dev server inside the container died or hung. Stop → Run preview.

A file shows a diff instead of the editor. It has a pending AI change. Accept or reject it first — see Editing files.

Attachment refused. Over 4 images, over 5 MB, an unsupported type, or a model without image support. See Attachments.

In your app

getaddrinfo / ECONNREFUSED on the database DATABASE_URL was edited by hand. Restart the preview; Qyant rewrites the managed values.

relation "…" does not exist A table the code expects hasn't been created. Ask the model to add table creation for it, following lib/items.ts.

Environment variable is undefined Added to .env but the preview wasn't restarted; or the variable is used in browser code without the NEXT_PUBLIC_ prefix.

Hydration mismatch warnings Usually a date or random value rendered on the server and again on the client. Ask the model to move it into an effect or format it consistently.

Account

"Sign-in link expired" Codes are single-use and short-lived. Request a new one.

Google / GitHub sign-in returns an error The provider declined the authorisation, or you have an existing account with that email under a different method. Sign in with the original method, then link the provider from Settings.

Can't upgrade / checkout doesn't open An ad-blocker is likely blocking the payment overlay. Allow paddle.com for qyant.dev, or try another browser.

Something else

Contact support with the project name, what you did, and the exact message. Screenshots help.