It is not the first time that this happens.
I created a rule and forgot to paste it in the grammar.xml from the Wikipedia tool.
Then, I ran a check against 200 000 sentences, and it produced a 1 kB file.
To make sure the rule was solid, I ran another test against 600 000 sentences and again no hits.
Then I found out that the resulting .txt file said that the rule didn’t exist (because I forgot to paste it).
My suggestion is if it could be possible to enhance the tool to abort a check if the rules don’t exist.