My Adminstration screen generates a blank page after the AllEvents update
The Administrator AllEvents LiveUpdate plugin has been replaced by the LiveUpdate Joomla. Nevertheless, it's still active that is thereason of the blank page.
To deactivate it:
Goto the webpage: ~administrator/index.php?option=com_plugins&view=plugins
Deactivate the Quick Icon - AllEvents :: Update Notification
And it's OK