WordPress ‘Missing Schedule’ issue understanding

The very annoying ‘Missing Schedule’ Wordpress issue is not a Wordpress-issue, it’s a server-side configuration problem. I learned this from some trial test in collaboration with my hosting provider.

I’ve encountered issues with WordPress missing scheduled posts and not sending them online on various photography related websites that I run or am involved with. The ‘Missing Schedule’ issue is not unknown and mistakingly sometimes called a bug of WordPress. Various solutions have been proposed and I’ve discussed them here, to some extent.

As many others, I struggled quite a bit in understanding what’s behind and how to best handle it. Initially, when contacting the support of one of my webhosters, I got the answer that they cannot help with application specific issues, which is a very typical, but understandable. But I finally got his attention when I told them that it’s all running smoothly on hosting accounts with two of his main competitors. And we found the cause:

It’s a server-side setting issue. Overly secure server settings might prevent WordPress from accessing it’s own cron-like functions. WordPress needs to call back to itself and on this particular webhoster (not the one running this blog here) mod_secure was loaded with PHP. After deactivating it, it all worked fine. If you can’t get your hoster to change this, you probably have to go the define(‘ALTERNATE_WP_CRON’, true); way, described in my previous post.