Sharexy plugin conflict namespace. Class SharexyErrorReporter, SharexyWidget, SharexyAdmnin, SharexyMain is all ready exists. "; return $content; '); add_filter('the_content', $sharexyErrorCallbackFunction, 20); add_filter('get_the_excerpt', $sharexyErrorCallbackFunction, 20); } else { require_once "SharexyError.php"; require_once "SharexyMain.php"; require_once "SharexyWidget.php"; require_once "SharexyAdmin.php"; require_once "SharexyView.php"; require_once "SharexyJson.php"; require_once "libs/bitly.php"; $sharexy = new SharexyView(new SharexyWidget(), new SharexyAdmin(), new SharexyErrorReporter()); $sharexy->initWidget(); $sharexy->initAdmin(); }