If you are using Alex popularity plug-in then you might face this error while upgrading plug-in automatically in WP 2.5. This error generate due to invalid wp-header file path in plug-in file. Unfortunately, Alex not released new fixed version of the this popular plug-in. However, fix is really very simple and anyone can fix issue just by editing one single plug-in file. Please follow steps below to fix this error in your installation:

  1. Deactivate older version of the plugin. If you are installing first time skip this step.
  2. Download the latest release from wordpress.org or plugin author website.
  3. Open popularity-contest.php in your favorite editor and scroll down to line 59. Replace
    require('../../wp-blog-header.php');

    with

    require('../wp-blog-header.php');
  4. Save file and upload file to your plugins folder.
  5. Reactivate the plugin

Written by Hemant Patel

Hemant, hailing from Bhopal, Madhya Pradesh, India, is a web developer and occasional blogger passionate about exchanging ideas and addressing problems in his coding journey.