Error 401 or The required information to complete authentication was not provided or was incorrect.

Content

Almost all pages on https://console.us-ashburn-1.oraclecloud.com/ show "The required information to complete authentication was not provided or was incorrect.". I've tried login/logout many times, I've cleared all cookies, and even tried Incogninto mode, but still get the same error. In the "Inspect" I see a lot of "401" errors, including https://identity.us-ashburn-1.oraclecloud.com/:

{
  "code" : "NotAuthenticated",
  "message" : "The required information to complete authentication was not provided or was incorrect."
}

I suspect that something is wrong with my account (it was switched from Paid to Free) recently, and now I can't even open "Upgrade" page because of the same error.