This same error message has been reported by multiple users:
- Manual registration of DOI in Crossref failed
- DOI registration server returned an error:
- [OJS] Crossref plugin Submission was not successful! - #4 by asmecher
- Register DOI with CrossRef
@birkok reports contacting CrossRef, where they responded that this was not an issue on their end. This seems highly unlikely, however. Has anyone else contacted CrossRef regarding this error message?