Problem caused after having updated my plesk from 8.1 to 8.2

[SHELLHOSTER]

Hello,
after having updated my plesk, i can not longer have access to the plesk login page which is https://my-ip:8443/. The adress in the navigation bar changed to https://my-ip:8443/login.php3?previous_page=index

and what is displayed on the page instead of the login form is :

ERROR: PleskFatalException
Components::componentUpdate() failed: Unable to exec utility packagemng: Empty error message from utility.

0: /usr/local/psa/admin/auto_prepend/auth.php3:508

Is there a way to solve this problem please? Remember its a bit hard to restart the dedicated server..

Thanks for giving me your help..

Regards
Malek