I recently upgraded my wordpress blog from PHP 7.1 to 7.2. After that, I started getting an error on the top of the pages: “Warning: Use of undefined constant”, pointing at what I previously set on wp-config.php: DISABLE_WP_CRON
I used this to disable the cron triggering with user access, instead I set up a manually cron job that runs every 20 minutes and open the wp-cron.php
The instructions I used asked to use the following format:
Turns out PHP 7.2 does not like it.
The undefined constant error is quite generic, but in this case the fix is quite simple. Just declare like this instead:
define( ‘DISABLE_WP_CRON’, ‘true’);
I suspect some plugins might be affected by this too, but so far all the stuff I’m using is very up to date, so no issues yet!