After clicking finish in the subreport creation wizard, the following message appears while loading the Designer:
Error loading the report template:
org.xml.sax.SAXParseException: Invalid encoding name "UTF8".
<?xml version="1.0" encoding="UTF8"?>
in the generated jrxml file, and the UTF8 string is not recognized by the sax parser as valid encoding.
<?xml version="1.0" encoding="UTF-8"?>