I use the wordpress plugin Counterize II to track who visits my websites. I recently noticed the plugin did not report any information for one of my sites. At first I thought it was a database issue, but upon looking into it, this was not the case.
I tried all sorts of methods to fix it: I deactivated and reactived the plugin, uninstalled and reinstalled the plugin, and messed around with the database tables. None of these methods worked.
As a last resort, I thought it could be related to the theme I was using since I had made some changes to it. I double checked all the changes I made and they all seemed benign. So, I began to look through the Counterize II code to see what function actually gets called to record the site hits and how it gets called.
It turns out, that Counterize II gets called through a wordpress API hook. Looking further into the problem, I realized that my theme never calls the function that is to invoke the hooks, specifically, the wp_head() function.
After some more searching, I found this website which helped me fix my problem. For Counterize II to function, you have to have
<?php wp_head(); ?>
somewhere inside your <head> HTML section. I added that line of code and Counterize II now works!