I just installed Magento2 platform. The admin page was blank showing gray screen without anything. I enabled the error to be shown then its displaying this error and I didn't found any solution or reason of it:
There has been an error processing your request
Class Magento\Framework\View\Element\Template\File\Validator does not exist
What is the Magento2 version that you are installing?
Could you set Mode to developer and send me the trace on var/log/system.log?
See how to set Magento2 modes here
Thanks