The blank page was showed When I upgrade the site from 3.0.2 to 3.1. I checked the error log.
At the end of log, it showed
[20-Dec-2017 09:40:20 Asia/Shanghai] PHP Fatal error: Call to a member function getId() on a non-object in /home/wwwroot/lanmp5.3/domain/openjournal.com/web/classes/install/Upgrade.inc.php on line 2480
How can I fix this
Thanks in advance