[Crossref Testing] error when registering DOIs
Issue description; A number of errors came up in Crossref when testing publishing via Crossref Testing site. They occurred on Wednesday and Thursday last week only. Articles published on Friday and today were successful. The error message is the same for all failed objects (from what I can tell);
Deposited XML is not well-formed or does not validate: Error on line 98: An invalid XML character (Unicode: 0x2) was found in the element content of the document.: Error on line 98: An invalid XML character (Unicode: 0x2) was found in the element content of the document.