Updated Lay Theme (along with the default themes) today, and after the update finished, my wordpress install appeared to be broken. Whenever I tried to access the backend or any URL, I got this error:
Parse error: syntax error, unexpected '[' in /home/redacted/public_html/2015A/wp-content/themes/lay/assets/inc/simple-custom-post-order/simple-custom-post-order.php on line 145
I tried looking for an extra '[' in the simple-custom-post-order.php file but couldn't find it.
I had FTP access so I found the simple-custom-post-order on wordpress.org and re-installed manually. This fixed the issue!
Just posting for posterity!