Fix: WordPress administration UI content area showing up blank

Some time ago, at a WordPress 3.3 blog, a friend was getting a blank main area at the administration UI (just the menu was showing up there) when they visited the classic URL of the form http://somesite/wp-admin/. Here is a writeup of some notes I had kept while troubleshooting that issue and then upgrading to newer WordPress, with updated theme and plugins.

Visiting the problematic admin UI page online, I right-clicked and selected View Source in the browser and browsed to the bottom of it where it was showing: 

That div tag wasn’t not closed with a matching closing div. Obviously some PHP code that was outputing that tag failed at that point.

For starters, I copied all files via FTP (with the FireFtp Firefox plugin) from the remote server locally (into my Dropbox). Useful for backup too in case I messed up something.

Could use grepWin tool (http://stefanstools.sourceforge.net/grepWin.html) to search all locally copied php files for “contextual-help-sidebar” and see which one was outputing this (if that string was assigned to some variable could then search again where that variable was being used).

However, WordPress also has debugging mode, so I edited wp-config.php and uploaded the edited version to the server replacing the old file. I changed WP_DEBUG setting to true below: 

 

At the problematic admin UI online page again, I right-clicked and selected View Source in the browser and browsed to the bottom of it, this time reading:

This led to indentifying the exact place in the PHP code that was causing this issue:

So, I commented out the buggy PHP code, converting it to an HTML comment block instead of a PHP block:

and the admin UI was working again after I pressed ENTER at the address bar again to refresh the admin UI (http://somesite/wp-admin/) and it was not showing up fine (F5 function key didn’t seem to really refresh the site when using Firefox btw, probably some caching issue).

Then installed (the free version) of the WP Database Backup plugin for WordPress:

http://www.wpseeds.com/documentation/docs/wp-database-backup/

by searching for “Backup” at

http://somesite/wp-admin/plugins.php

and evaluating the different backup plugins listed there (judging from both their votes and by checking out if WordPress wasn’t saying at the details page of a plugin that it hasn’t been tested with that [old] 3.3 WordPress version that was on that site) and backed up from Tools/WP-DB Backup menu:

http://somesite/wp-admin/tools.php?page=wp-database-backup

Then Downloaded the MySQL backup (.sql) file, so now I could update Themes, then Plugins, then update WordPress to new Core from

http://somesite/wp-admin/update-core.php

Did keep copies of the wp-content/themes and wp-content/plugins folders before and after updating them of course.

After WP updated, it asked to update the DB, all went ok

Then did backup up again the database via the WP-DB Backup tool and went again to

http://somesite/wp-admin/update-core.php

and installed an update for one of the plugins (can also do update per-plugin from http://somesite/wp-admin/plugins.php)

Then backed up again every file (db not included there) via FTP and done.