Good Afternoon Codeforces,

This question is directed at those familiar with the Polygon platform. At present I'm trying to put some recent regional problems into Polygon for a mashup contest. Upon verifying the solutions/data, I get the following result:

PackageException: LongLongStrings_sjz2_pacnw.java got FL on judge#20 which violates tag ACCEPTED.

I can not find anything in the Polygon documentation about "FL". Does anyone have a clue what this means? Thanks in advance.