java - BeanIO - UnidentifiedRecordException when parsing UTF8 file -

i have problem when parsing file encoded utf8.

i have 2 files identical, except encoding. (i copied file , saved utf8, contents identical). 1 encoded using ansi, other utf8. file encoded ansi succesfully parsed while other file causes beanio throw unidentifiedrecordexception when calling beanreader.read() method:

org.beanio.unidentifiedrecordexception: unidentified record @ line 1 

i have tried solve explicitly setting encoding utf8 using code:

public static beanreader getbeanreader(file file, streambuilder builder) {      streamfactory factory = streamfactory.newinstance();      factory.define(builder);      inputstream istream;      try {          istream = new fileinputstream(file);      } catch (filenotfoundexception e) {          throw new customexception("could not create beanreader, file not found", e);      }      reader reader = new inputstreamreader(istream, standardcharsets.utf_8);      return factory.createreader("reader", reader); } 

which doesn't solve issue.

what reason error?

as first line claimed erroneous, did save utf-8 without bom (that infamous zero-width space @ file start)?