Problems/Error when Update Plesk 7.5.4 to 8.0.0

[limoncenter]

OS: Linux Fedora Core 2
Plesk: Plesk 7.5.4 to Plesk 8.0.x

Hi masters ... i have a problem in my ded server, when i try to access/entry in the web panel ... this ERROR present:

Server >
ERROR
Up LevelUp Level
StatInfo->getProductVersion failed: file_get_contents() failed:
0: /usr/local/psa/admin/plib/common_func.php3:25 psaerror(string "StatInfo->getProductVersion failed: file_get_contents() failed: ")
1: /usr/local/psa/admin/htdocs/index.php:140 getProductNameVersion()

I updated the Plesk Control Panel 7.5.4 to 8.0.0 through Plesk Updater ...

Somebody knows why is this problem? and how i can fix ?

THANKS i appreciate your time.