[TYPO3-english] Fatal error: Call to undefined method TYPO3\CMS\Extbase\Utility\ExtensionUtility::getPluginNamespace

[Litwiniec Adam]

Hello,

after update 4.5LTS->6.2LTS I can't run backed -work but I can't start frond end preview.
After run 'view page' i got Error message:

Fatal error: Call to undefined method TYPO3\CMS\Extbase\Utility\ExtensionUtility::getPluginNamespace() in /var/www/autobid-t3-al2/htdocs/typo3conf/ext/ed_extbase/Classes/Core/Bootstrap.php on line 50 

Can someone help me?
Many thanks

Adam