If the first field of a type is a group - it will not build the group

in parseGroup method in Message.java - it checks if it's parsing the first field and sets it. But if this is a group groupDataDictionary.isGroup(msgType, field.getField()), the group parsing never happens. Adding the following code after "previousOffset = -1;" resolves the issue:
if (groupDataDictionary.isGroup(msgType, field.getField()))

{ parseGroup(msgType, field, groupDataDictionary, group); }