Error admin after update

[thierrys]

Helo,

After update 9 > 10 , when i want to connect to admin, i have this message :

ERROR: Zend_Log_Exception
"/usr/local/psa/admin/logs/panel.log" cannot be opened with mode "a"

0: Stream.php:66
Zend_Log_Writer_Stream->__construct(string '/usr/local/psa/admin/logs/panel.log')
1: Abstract.php:84
CommonPanel_Application_Abstract->_initLog()
2: Abstract.php:31
CommonPanel_Application_Abstract->run()
3: Abstract.php:19
CommonPanel_Application_Abstract::init()
4: auth.php3:137

Can you elp me ?

Thank you very much

Thierry