PFSense in Hyper-V / Class Pear not found in Chap.php

[karifuik]

Hello there
I am running instance of PFSense 2.4.3 in Hyper-V 2012.
Since latest security update of Hyper-V, i cant logon on the GUI of PFSense and when i connect to console and try to restart or update PFSense from console, i receive this error message:

Fatal error: Class ´Pear’ not found in /usr/local/share/pear/Crypt/CHAP.php on line 57
PHP ERROR: Type: 1, File: /usr/local/share/pear/Crypt/CHAP.php, Line: 57, Message: Class ´Pear’ not foundHyper-V Virtual Machine

Can somebody help me ?
Thanks very much in advance.

John