I've experienced this too, just now again actually. The problem lies (at least in my case) in the permissions and file ownership on the server. I had a blank screen, no errors on screen, none in the console, none in the var/ logs. I tried to get errors out of the system by adding the error_reporting(E_ALL); and ini_set('display_errors', 1); to the index.php - no results whatsoever.
But I found tons of errors like this in the serverlogs:
PHP Fatal error: Uncaught Magento\\Framework\\Exception\\LocalizedException: Can't create directory
Because I've been badgered by "Can't create directory" and other permission-related error in Magento2, I've asked my hoster to make a bash-script to check and fix all permissions for a Magento installation via ssh. So whenever I get a blank screen, I run the script to fix the permissions and everything's okay again.
TL;DR: pretty sure you have to fix the permissions/ownership of files
