The permission window was closed or interrupted

If the approval step is cancelled or the popup is closed, Pinterest returns without a usable connection.

There is no usable board for publishing

A connection can succeed more cleanly when the business account already has a board that is ready to receive new pins.

Pinterest tokens can stop working after account security changes or leaked-token revocation, which means the account needs a fresh authorization.

Make sure the account already has at least one board you can publish into.

Approve the requested board and pin permissions instead of closing the popup early.

If your workflow depends on website attribution inside Pinterest, finish claiming the website in Pinterest first.

Retry from a fresh authorization step instead of reusing an older callback or login attempt.

Pinterest opens, but the boards you expect never appear. This usually means the browser is signed into a different personal or business account.