Categories page was missing

I’m using the marvelous Atahualpa theme, with many customizations. One day, I noticed that when I clicked on Categories under Posts in the dashboard, I got a blank page. My categories were still working, but I just couldn’t see them that way. They would appear if I clicked on the categories link under the Right Now/At a Glance link. I started worrying that I had a bad database table.

I asked the ISP guys to repair the tables, which they did. No change.

I deactivated several of the more recent plugins. No change.

Then I looked at the WP files. I noticed that in wp-content/plugins, there was a file called categories.php. What?? There’s one called category.php in wp-includes too. What’s going on? I looked at the code for categories.php, and found this:

/**
* Advanced categories widget
* Replaces the default WordPress Categories widget
* Arguments are input through the widget control panel
*
* @since 0.1
*/
function widget_reloaded_categories($args, $widget_args = 1) {
_________
I must have deleted that plugin at some point, and the artifact file was left behind, interfering with the default page. I think it was Advanced Category Excluder.

I deleted the file, and now everything is working fine again.

There was another thread about the missing categories page, and people had various ways of dealing with it, including repairing the wp_posts table. Since that didn’t work for me, I thought I should let folks know about this other possibility. Maybe this only happens with the theme I’m using. Anyway, I hope this helps someone else.