workflowService.getAssignedTasks Castor Marshall Exception

com.rivetlogic.core.cma.exception.CmaRuntimeException: org.exolab.castor.xml.MarshalException: Invalid byte 2 of 3-byte UTF-8 sequence.{File: [not available]; line: 2; column: 267}
   at com.rivetlogic.core.cma.mapping.impl.CmaCastorUnmarshaller.unmarshal(CmaCastorUnmarshaller.java:57)
   at com.rivetlogic.core.cma.rest.impl.RestExecuterImpl.processResponse(RestExecuterImpl.java:403)
   at com.rivetlogic.core.cma.rest.impl.RestExecuterImpl.processResponse(RestExecuterImpl.java:331)
   at com.rivetlogic.core.cma.rest.impl.RestExecuterImpl.execute(RestExecuterImpl.java:113)
   at com.rivetlogic.core.cma.rest.impl.RestExecuterImpl.execute(RestExecuterImpl.java:95)
   at com.rivetlogic.core.cma.impl.WorkflowServiceImpl.execute(WorkflowServiceImpl.java:564)
   at com.rivetlogic.core.cma.impl.WorkflowServiceImpl.getAssignedTasks(WorkflowServiceImpl.java:261)
   at com.forge.corp.sopra.AlfrescoService.getTasks(AlfrescoService.java:68)
   at com.forge.corp.sopra.Main.main(Main.java:9)
Caused by: org.exolab.castor.xml.MarshalException: Invalid byte 2 of 3-byte UTF-8 sequence.{File: [not available]; line: 2; column: 267}
   at org.exolab.castor.xml.Unmarshaller.convertSAXExceptionToMarshalException(Unmarshaller.java:761)
   at org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:727)
   at com.rivetlogic.core.cma.mapping.impl.CmaCastorUnmarshaller.unmarshal(CmaCastorUnmarshaller.java:55)
   ... 8 more
Caused by: org.xml.sax.SAXParseException: Invalid byte 2 of 3-byte UTF-8 sequence.
   at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
   at org.apache.xerces.util.ErrorHandlerWrapper.fatalError(Unknown Source)
   at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
   at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
   at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
   at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
   at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
   at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
   at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
   at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
   at org.apache.xerces.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
   at org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:715)
   ... 9 more