Separate browser, domain and hosting issues before making changes.
What to do
- Record the exact URL and error; try another browser or network.
- Check hosting status and related invoices in the portal.
- Check domain expiry and DNS.
- List recent plugin, file, DNS or migration changes.
- Send the address, error, start time and changes to support.
Check the result
A problem on only one network may involve local caching.
If you need a hand
Do not reinstall WordPress or delete files as a first response; it can make recovery harder.
Open a support request. Include the affected domain and what you tried. Leave out passwords, full payment details, and private keys.