Multisite Conversion White Screen Error

Question

After converting a site to multisite configuration, I get a white screen when trying to browse one of the subdomain sites.

I have configured the site according to this: Wordpress Codex - Create a Network

The main site loads without a problem, but the test site I've created at a subdomain just returns a white screen.

I have the subdomain configured like this:

*.mywebsite.com

Which points at the root directory where the main website lives.

The site has been configured in the Network Sites Admin in Wordpress.

Checking the error logs reveales only a couple of warnings related to plugins, but each time I deactivate those plugins I still get the same white screen.

Are their any other troubleshooting steps I can take to get this resolved?

MORE INFORMATION

I guess for the multisite conversion, the database replicates tables with a different prefix. Here's an example of one of the warnings thrown:

[Mon Dec 07 22:45:11 2015] [warn] [client xxx.xxx.xxx.xxx] mod_fcgid: stderr: WordPress database error Table 'dbname.wp_2_wpeditor_settings' doesn't exist for query SHOW FULL COLUMNS FROM `wp_2_wpeditor_settings` made by require('wp-blog-header.php'), require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('init'), call_user_func_array, WPEditor->init, WPEditorSetting::setValue

So does this mean I need to delete and recreate the site to replicate those other tables?

MY CURRENT ASSUMPTION

After a little more research, I believe a subdomain multisite installation WITH AN SSL requires a Wildcard SSL, which is what I don't have currently. Could someone confirm or weigh in on that?

Answer 1

Since you're not getting anything in the page source, it's at least reasonable to work under the assumption that something is either going wrong in the initialization process or very early on in building the page templates (like something you've hooked into wp_head().

I would try adding "breakpoints" to any functions that you've hooked into the init or wp_head actions and see how far you get.

I usually echo something simple at the beginning of each function:

echo "<h1>APPLES</h1>";

I use a different fruit each time so that I know I'm progressing deeper into my code. When you don't see the output, you'll know you've zeroed in on the cause of your issue.

There are some additional ideas here: White screen error for a custom theme