[TYPO3-english] Manage extensions menu NOT available anymore?

[joel zimmerli]

I just installed the extension "doc_indexed_search" (it was already available in the Typo3 structure, I just have to install it) and the extension works fine.

BUT... after this installation, the menu to handle the extension in the BE disappeared! A new menu "Indexing" is available but I cannot get access to the menu to see the list of extension, etc.

Is that a known problem, how can get this very important menu back?

Thank you in advance for your help.
Bad.