Clear the cache.

Dear all,
Our drupal site is installed on a remote server.
This afternoon i installed few Drupal modules (internationalization and variables). After activation of those modules, i noticed that my admin menu (content/structure/configuration/users,....) had disapeared.
I don't know why. According to you, is there a way to recover the admin menu?
I'm very annoyed by this problem.
In advance ,thank you very much for your help.