Thanks for your inquiry. You have attached template Word document and XML data file with your first post. However, please also attach simplified Java source code you used to build report on your end.
First off, I have attached a template Word document and XML file against which Aspose.Words is able to successfully build report using following code:
Document doc = new Document(getMyDir() + "TemplateWithUTF8-correct.doc");
ReportingEngine engine = new ReportingEngine();
DataSet ds = new DataSet("items");
ds.readXml(getMyDir() + "data4-correct.xml");
engine.buildReport(doc, ds);
doc.save(getMyDir() + "15.8.0-correct.doc");
Secondly, when adding UTF-8 characters such as  at the beginning of field, Aspose.Words throws following exception:
java.lang.IllegalStateException: An error has been encountered at the end of expression ‘req in Â’. Character ‘Â’ was unexpected at this position.
For the sake of correction, we have logged this problem in our issue tracking system as WORDSNET-12479. Our product team will further look into the details of this problem and we will keep you updated on the status of correction. We apologize for your inconvenience.