plesk panel 11.5 ERROR: Call to undefined method Zend_Validate_Abstract::hasDefaultT

[MrCadillaC]

pressing the button "OK" ANY WAY part

shows the following error:

Internal error.
ERROR: Call to undefined method Zend_Validate_Abstract::hasDefaultTranslator() (Element.php:1358)

 

[SvetlanaS]

not enough info.
Upgrade?
Plesk version-11.5.?
Php version?
Under which conditions you have such issue&