Refresh once if a read-only page appears incomplete. If the same error returns, check another page, a private window, or another network; compare official status and recent user reports. Those tests help separate a browser problem from a broader service issue.
Do not repeatedly resubmit checkout, booking, or form actions. A request can succeed on the server even when the confirmation fails to appear, and retrying may create duplicates. Check order history or confirmation email before attempting it again.
Preserve the exact error and time instead of erasing evidence with endless reloads.