New Sidebar
Why did you change the sidebar? The new sidebar is unsuitable for working in translatewiki.net. Translatewiki is not like another wiki project like e.g. Wikipedia. Please restore the old sidebar.
What's wrong with it?
Nike
What's wrong? All typical links for translators don't exist: the link to the translation tool, the link to the Support, the link to the news etc. Alle the links which existed before are now missing. The sidebar should support translators and not any normal users.
In these cases, you can try to make a "null edit" to MediaWiki:Sidebar. That usually resolved the issue. The origin is unknown.
That page is protected for me, wouldn't it be for him as well?