Ahh… sometimes the smallest things can prove to me the most frustrating. After fighting with high CPU usage on my Bitnami install I decided to give W3 Total Cache another try. I installed the plugin, set it up, tested a few pages and everything seemed to be working. Even a bit speedier (yah!).
So I carried on browsing around my Wordpress site and then I noticed that all my tag and category pages were blank. what?! I was almost confident that I saw them working just fine a few days ago. I thought the problem would be simple to fix – after all, I hadn’t really changed anything configuration-wise on my site for at least a week or two. And the one change I did make was easy to undo.
I was so right, and so wrong.
First I tried deactivating W3 Total Cache – seems obvious that the most recent thing would have caused the problem. Nope. I tried toggling the permalink settings in Wordpress, and recreating my .htaccess file. Nothing, the pages were still blank. I remembered installing mod_pagespeed recently, so turned it off and restarted Apache. nothing.
Then I took a flyer – maybe saving a new AMI had caused some weirdness. I restarted the instance and the same friendly white page stared back at me. I restarted Apache again (you can never restart too much, right?) and ended up in the same place.
In desperation I turned to Google and found this Wordpress help article on how to fix permalink problems in Wordpress. Ahh, I’d have to brave a few more changes to httpd.conf. I changed my AllowOverride – still nothing – of course I knew this wasn’t the source of the problem because I had good evidence that the rewrite rules in .htaccess were getting picked up. I flirted with this advice for fixing custom permalink and trackback 404 issues, but decided against trying it – the symptoms were very different than mine, and I wasn’t thrilled with editing random .php files in my Wordpress install.
A Solution! Blank category and tag pages in Wordpress begone!
It was only through happenstance that I stumbled on the solution. I changed the permalink structure from ‘tag’ to ‘tags’ in Wordpress, and it worked. ‘Hmmm’, I thought to myself, ‘ that doesn’t make any sense’. I changed it back and it stopped working. I changed the permalink for categories to ‘c’ and tags to ‘t’ – and resigned myself to the SEO hit I’d get from this. At least I’d get a shorter URL, right?
Then something strange happened. Categories worked, and tags loaded a weird page I’d used for testing a while back. Then it hit me!
I had category.php and tag.php files in my Wordpress base directory. OMG! I remembered mistyping a copy command about a week back, and thinking nothing of it. This was the problem! I deleted those files, set category and tag redirects back as they were before and Viola! it worked.
So the solution was simple. Trivial. Yet not obvious until I stumbled across it.
That’s one of the reasons I love computers. They do just what you tell them to. Even when it’s not what you want them to do.