Cause
The credential is not valid, has expired or was revoked. The response includes WWW-Authenticate.
What to do
Tokens last 15 minutes: request a new one. If you use an API key, verify that it has not expired or been revoked.
application/problem+json
{
"type": "https://masnet.com/developers/errors/invalid_token",
"title": "Invalid credential",
"status": 401,
"detail": "...",
"code": "invalid_token",
"correlation_id": "..."
}