Erro emissor gratuito NF

Do nada o emissor passou a aparecer esse erro inesperado, alguém sabe o qu epode ser?

AxisFault
 faultCode: {http://www.w3.org/2003/05/soap-envelope}Server.userException
 faultSubcode: 
 faultString: org.xml.sax.SAXException: Processing instructions are not allowed within SOAP messages
 faultActor: 
 faultNode: 
 faultDetail: 
{http://xml.apache.org/axis/}stackTrace:org.xml.sax.SAXException: Processing instructions are not allowed within SOAP messages