Upgrade to version 4.7.31 seems to have broken DAO.PHP
Version 4.7.31 was installed and now an hourly cron job is erroring like this:
"Parse error: syntax error, unexpected '[' in /.../administrator/components/com_civicrm/civicrm/CRM/Core/DAO.php on line 651.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information