Last modified: 2014-02-12 23:38:09 UTC
Goto [[w:de:Spezial:Missbrauchsfilter/test]], use rule #17 with "changes by user" = 84.167.232.67. This will trigger some edits. Now add the line | (rcount("something",added_lines) < rcount("something",removed_lines)) somewhere in the rule. Then it will fail. Maybe there is a maxmum length of filter rules? (Filter rule #3 at w:de was very long (> 1000 chars). A work-around was to move a part of the rule to #17.)
(batch change) Minor bugs that nevertheless need looking into
The maximum length is 65, 536 characters. I don't think it's likely that you're hitting it, though. The filter seems to not match, rather than throwing a syntax error.
Problem may be the max URL length.