If you are using rather exotic Windows regional settings you might get the following error:
Locale not recognized
The solution is simple as mentioned here. Just set the JAVA_TOOL_OPTIONS environment variable to this:
-Dfile.encoding=UTF8 -Duser.language=en -Duser.region=US -Duser.country=US
JDBC won’t use regional setting to determine locale to be used (and probably unsupported at the moment) anymore .