To reproduce this bug:

1. Go to the special page Create item on the repo - http://wikidata-test-repo.wikimedia.de/wiki/Special:CreateItem
2. Hover with the mouse over the question mark next to Enter label
3. The message "Enter the title of this data set in null" appears.
4. An similar bug occurs when the mouse is hovered over the question mark next to enter description.

The bug is that the parameter in [1] and [2] is shown as null, but it should be the name of the language (in this case "English").

This bug affects only the special page Create Item. The message is displayed with the language name as expected on items that have been created.

[1] http://www.translatewiki.org/wiki/MediaWiki:Wikibase-label-input-help-message/en
[2] http://www.translatewiki.org/wiki/MediaWiki:Wikibase-description-input-help-message/en

Version: unspecified
Severity: minor