Child Theme throwing White Screen

Hey folks,

I’ve written my own parent and child theme pair. Been at WP for years, so I’ve created a parent theme of my most common functions and template types, which I’m tapping into. This is the first time I’ve tried using a child theme to extend the parent and I’ve run into a problem.

For a start, the site is working perfectly on my local install and on an in-house test server. The issue only occurs on the live server.

The site works perfectly on live with the TwentyFifteen themes active, it only breaks when my theme is activated.

Finally, I have tested this without any plugins installed and with all the required plugins installed. In both cases the issue remains.

The issue is that, when updating or changing content or certain settings on the site, I get a white screen.

An example: I create a page or post, and click Update. I get a white screen. If I return to the pages/posts parent, the page has been created.

I install a plugin. The plugin install process commences. At the final step of install, when I click “Activate”, I get a white screen. Return to the plugins page, the plugin is installed and active.

Finally (and this one is the most weird), in the media view, I get the list of uploaded media. When I select grid view, the page changes to grid, but the spinner just spins, without loading any media content.

The site uses only two plugins that I have used extensively in the past:

– Advanced Custom Fields
– Post Types Order

I’m now completely baffled. Like I say, none of these issues are occuring on local or on test environments. On live, I’ve even done a completely clean install, with no content in the DB. As soon as I activate my theme, I run into these issues. The errors logs return no errors. I turned on debugging and resolved even all the notices I was getting, there are no more errors. I’ve upped the memory to 256M (just to be certain). Still no resolution.

I understand my problem is quite vague, but I really can’t explain it much better. Host is Blacknight, a well known, well respected Irish hosting company (for an Irish client). Again, used their products on multiple occasions in the past without issue.

I suppose my main issue is, I have no idea how to debug this any more than I have done. If anyone has any pointers at all, I’d really appreciate the feedback. I think my next step will be to merge the parent and child into one and see if the issues continue.