A RulesetNotFoundException occurs, when loading rules (Rule.rulesFromUrl(..)) from a text file that contains umlauts in comments.
I wasn't aware of that, but yes the file is encoded in latin-1. However, I found it confusing that a 'NoRulesetFoundException' was thrown when the file obviously existed. Apart from the file's location there was no indication of what exactly the problem was.
Anyway, here is the code, a sample rule and the exception I am getting.
(?x rdfs:label ?y)
(?x ex:hasLabel ?y)