In ruWP AbuseFilter Messages shown as html.
When editing AbuseFilter, preview works good. But when AbuseFilter react for abuses, as I undestand, it converts wiki-code of messages to html, but then convert it to text ( < and &rt;instead of < and >), so user see only html-code, but not correct message.
It looks like this screenshot https://ru.wikipedia.org/wiki/File:AbuseFilterMessageBug.png
But it should look like this message https://ru.wikipedia.org/wiki/MediaWiki:Abusefilter-warning-self-redirect