WP Super Cache Plug-In Broke My Self-Hosted WordPress Blog

Appearances can be deceiving. If you have visited the Endtime Prophecy Net Blog in recent weeks, you may have wondered why it has been so sorely neglected, and why there haven't been any new blog posts in such a long time. The truth of the matter is that my blog is very much up-to-date, with one or more posts being made on a daily basis. The appearance of neglect is actually the result of a serious problem which escaped my full notice and attention until now. Read on and learn more.

Yesterday afternoon I made a discovery on the Endtime Prophecy Net Blog which did not leave me very happy. If you operate a self-hosted WordPress blog, and also have the WP Super Cache plug-in installed, I strongly advise you to continue reading, because without your even realizing it, your blog site may possibly be affected by the problems that I am about to describe for you.

If you visit the WordPress forum at http://wordpress.org/support/, you will discover that there are quite a few troubleshooting posts which deal with a problem which -- according to the date of the posts -- has perplexed some self-hosted WordPress blog admins for at least the past three years.

The gist of the problem is this: When the WordPress blog admin is logged in -- which I assume is usually the case with most blog admins -- he or she sees the very latest blog posts on the front page. If the admin logs out, he or she sees older posts on the front page, which is not the way that WordPress is supposed to operate. In mentioning the problem, one admin described it as looking back in time at his blog. Not only were the posts on his front page old, but the sidebar was also an older version of his sidebar.

Well, to my dismay, yesterday I discovered that the Endtime Prophecy Net Blog has been affected by this very same problem for over six weeks, and I was not even aware of it, at least not fully. You see, like most WordPress blog admins, I do in fact remain logged in to my blog most of the time; and that is why I remained unaware of the full extent of the problem.

However, my problems were not just limited to old posts appearing on the front page when I was logged out, or old data being displayed in my sidebar. In addition, regardless of whether I was logged in or out, the Online Users widget in the sidebar would always show me as being logged in, and I never understood why it was doing this. I just assumed that it was a big buggy.

In addition to the log in status problem, even though I do not have the requirement set that a visitor must be logged in, in order to leave a comment on the Endtime Prophecy Net Blog, whenever I tried to post a comment while being logged out, my blog would inform me that I had to be logged in first in order to post a comment. Again, I had no idea why this was occurring.

My first inclination was to suspect that there was a caching problem somewhere. More specifically, I strongly suspected that WordPress plug-in developer Donncha O Caoimh's WP Super Cache 0.9.9.9. plug-in might be the problem. So, I spent some time playing around with the settings under the plug-in's various tabs. I deleted the cache a few times, deactivated and reactivated the plug-in,and tried a few other things. It was all to no avail. No matter what I did, the same four problems continued to persist:

1. Old posts on the front page when logged out

2. Old sidebar displayed

3. Saying I am logged in whether I am or not

4. Saying I must be logged in to post a comment, even though I don't have that option enabled in my settings

What motivated me to resort to drastic measures was the fact that while I was playing around with the settings, I walked into my daughter's room and asked her to go to my blog, so that I could determine what she was seeing as a non-admin, not-logged-in visitor. In other words, I wanted to make certain that the problem was not just limited to the admin account.

Well, you guessed it. She was also seeing the old posts on the front page. In fact, she told me that she had been experiencing this for a long time. Furthermore, during one instance while I was watching her, when she refreshed her page, her web browser tried to download the blog as a gzipped archive. Clearly, something was seriously wrong somewhere.

This latter point convinced me even further that Donncha's WP Super Cache plug-in was the culprit; because in his notes on one of the settings pages, Donncha even mentions the zipped archive problem; although he states that he is uncertain whether or not WP Super Cache is causing the problem. Personally, I am inclined to believe that it is. In fact, I am fully convinced that it is.

Now, here is the main reason why this situation has really irked me. When my daughter mentioned that she had noticed the problem for a long time -- even though she never told me about it -- I am assuming that she meant since August 17th of this year, because that is the date of the newest post that was being displayed when a visitor was not logged in, and that is the date of the newest post that I was seeing when I was not logged in either. Furthermore, it was during that same week that I installed the WP Super Cache plug-in on the Endtime Prophecy Net Blog.

In other words, unbeknownst to me, this problem persisted for over six weeks before I became fully aware of it. I can't begin to imagine how many visitors and potential blog members I have lost over the past six weeks; because when they arrived at the Endtime Prophecy Net Blog, and assumed that I hadn't posted since August 17th -- meaning my blog is dead, or at least neglected -- they became discouraged and just left. How many comments were never posted, because my visitors assumed that no one would ever read them? In Internet time, six weeks is a long time. It can make or break a website or blog.

Having fully realized the extent of the problem, and its potentially dire consequences, I decided that I had enough of the WP Super Cache plug-in. So, I proceeded to deactivate and delete every last bit of it from my blog directory.

A strong word of caution: If you determine that the WP Super Cache plug-in is also causing serious problems -- such as the aforementioned -- on your self-hosted WordPress blog, and decide to uninstall it, it is very important that you carefully follow the exact uninstall procedure, as it is outlined in Donncha's "ReadMe.txt" file for the plug-in. If you try to uninstall the plug-in any other way, you could very well end up breaking your entire blog. As a courtesy to you, following is a word-for-word extract from the WP Super Cache plug-in "ReadMe.txt" file:

----- Begin Quote -----

Almost all you have to do is deactivate the plugin on the plugins page. The plugin should clean up most of the files it created and modified, but it doesn't as yet remove the mod_rewrite rules from the .htaccess file. Look for the section in that file marked by SuperCache BEGIN and END tags. The plugin doesn't remove those because some people add the WordPress rules in that block too.

To manually uninstall:

1. Turn off caching on the plugin settings page and clear the cache.

2. Deactivate the plugin on the plugins page.

3. Remove the WP_CACHE define from wp-config.php. It looks like `define( 'WP_CACHE', true );`

4. Remove the Super Cache mod_rewrite rules from your .htaccess file.

5. Remove the files wp-content/advanced-cache.php and wp-content/wp-cache-config.php

6. Remove the directory wp-content/cache/

7. Remove the directory wp-super-cache from your plugins directory.

== If all else fails and your site is broken ==

1. Remove the WP_CACHE define from wp-config.php. It looks like `define( 'WP_CACHE', true );`

2. Remove the rules (see above) that the plugin wrote to the .htaccess file in your root directory.

3. Delete the wp-super-cache folder in the plugins folder.

4. Optionally delete advanced-cache.php, wp-cache-config.php and the cache folder in wp-content/.

----- End Quote -----

Important: After you have carefully followed the above steps to uninstall the WP Super Cache plug-in, I strongly advise you to open the .htaccess file that is located at the top level of your blog's directory, and make certain that the following rules are still in place:

# BEGIN WordPress

RewriteEngine On
RewriteBase /Blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /Blog/index.php [L]

# END WordPress

Please note that the RewriteBase path and the ReWrite Rule path in your .htaccess file may be different from mine. It all depends on where you have WordPress installed on your server.

In my case, what happened is that somehow, the "RewriteEngine On" and "RewriteBase /Blog/" lines were deleted from my .htaccess file. I don't know if WP Super Cache did this when I uninstalled it, or if I accidentally did it myself. Whatever the case may be, as a result, whenever I clicked on the "Leave a Comment" link under a post, my server threw me a 404 error. The minute that I re-added these two lines to the .htaccess file, the problem disappeared.

In addition, after uninstalling the WP Super Cache plug-in, I strongly advise you to visually inspect every single file and folder that was affected by the plug-in, and make certain that it has been restored to its previous state. In other words, make sure that all files and folders which were supposed to be deleted, were in fact deleted. Also make certain that any code or rules that were added to any of your blog's files by WP Super Cache, were in fact deleted.

Now, if you still remain unconvinced that the WP Super Cache plug-in was the root of my problems and the real culprit, then consider this. After totally removing the plug-in and its effects from the Endtime Prophecy Net Blog:

1. Even if I am logged out, the newest posts now appear on the front page, as they should.

2. Even if I am logged out, the most recent version of my sidebar is now displayed, as it should.

3. The Online Users widget now properly displays my current status; that is, logged in or logged out.

4. I no longer receive the message which says that I must be logged in to post a comment.

As you can see, every single previous problem evaporated once I totally purged the WP Super Cache plug-in from my system.

A final word . . .

I am not a PHP programmer or a WordPress guru; so I honestly don't know why the WP Super Cache plug-in was doing the bad things that it was doing. I don't know if it alone was the culprit, or if it was interacting with another plug-in, or plug-ins, to cause the problems. All I know, is that upon uninstalling it, all of my problems cleared up immediately.

To reiterate, going by comments on the WordPress forum site, the aforementioned problems with the WP Super Cache plug-in have persisted for at least three years. The fact that they are still occurring after so long a period of time indicates to me that, apparently, Donncha lacks the expertise to fix them. As a result, as much as I would like to continue using this plug-in myself, and recommend it to other WordPress admins, I honestly cannot recommend it to anyone at this current time. It just isn't worth the trouble in my view.

The above message represents my own personal experiences with the WP Super Cache plug-in, and may not be indicative of every WordPress admin's experience with the plug-in. Your mileage may vary; but at least you have been warned regarding potential problems in advance.