Those who use WordPress.com stats plugin on their self hosted WordPress blogs might be familiar with this plugin named WordPress.com Stats smiley remover.
If you use WordPress.com stats plugin you may have noticed that it adds a small smiley on the page footer. There is a plugin to remove this smiley named WordPress.com Stats smiley remover which removes that footer smiley. (you can remove that smiley without that plugin too)
I used this plugin on my blogs before i started removing the wordpress.com stats plugin smiley manually myself without the plugin. However, one of my blogs was still running this plugin (maybe i forgot to remove this plugin from there and do it manually) but today when i went to visit the blog, i saw this error saying:
Fatal error: Call to undefined method WP_Error::get_item_quantity() in /home/******/public_html/*********/wp-content/plugins/wordpresscom-stats-smiley-remover/WordPresscomStatsSmileyRemover.php on line 75
The fix to this was pretty simple, to disable the WordPress.com Stats smiley remover, but hey! I did it and the site still gave this error! even after i deleted the plugin after deactivating it too! So what’s the issue now? Well i was using w3 Total Cache plugin on my WordPress blog too. I did the empty page cache but it still gave error. It was fixed when i went to w3 Total Cache admin page and cleared all cache.
Hope it helps.