Java unable to decode € with UTF-8

In my application I load all Lines from a file with the content:

EUR=€

with this command

List<String> lines = Files.readAllLines(Paths.get(currenciesPath) .toAbsolutePath(), StandardCharsets.UTF_8);

but although the charset is set to utf-8 i receive the following error

java.nio.charset.MalformedInputException: Input length = 1

what do I have to do to decode the € symbol and other currency symbols like $,₤