Not a JWT, or the header or payload is not a JSON object.
The header names an algorithm other than RS256 (including none).
No key in EVE SSO's key set carries the token's kid, even after a refetch.
The signature does not match the header and payload.
The iss claim is not EVE SSO.
The aud claim does not name the client id and EVE Online.
The exp claim is missing or in the past.
The key set could not be fetched or parsed.
Why TokenVerificationError rejected a token.