About [[MediaWiki:Mwe-upwiz-source-ownwork-assert-cc-zero/en]]
Many messages, including this message, does not show any detail about the message (not even original English message). So it become too difficult to translate. I remember that I reported this problem some weeks before.
Do not translate message which don't show definition. Those messages are not used. I don't know what is the history of this message.
It looks like you hit this message while sources were being updated. It looks okay now.
http://translatewiki.net/w/i.php?title=Special%3ATranslate&task=untranslated&group=ext-0-wikimedia&language=ml&limit=2500 (gives no details on clicking the link), but http://translatewiki.net/w/i.php?title=Special%3ATranslate&taction=translate&group=ext-uploadwizard&language=ml&limit=100&task=untranslated gives details!
