This was initially a vBSEO problem and the fix is well documented. The problem has more recently returned due to Yahoo dropping support for their Yahoo interface. New versions of vBulletin, both 4 and 5 are shipping with an empty uploader.swf file. However in some cases upgrading the version from 2.7.0 to 2.9.0 will also fix the issue.
To fix the redirect using vBulletin’s solution simply;
- Locate uploader.swf (vB4.xx - clientscript/yui/uploader/assets orin 5.xx- /core/clientscript/yui/uploader/assets)
- Open and delete file contents. Save.
- In admincp go to plugin manager and disable then re-enable a plugin. This clears the forum cache.
- Test using an a fresh incognito browser window
If you want to try a currently working version of the Yahoo User Interface, you’ll need to replace version 2.7.0 with 2.9.x.
- Got to Settings -> Options -> Server Settings and Optimization Options and set Use Remote YUI setting to use Google remote hosting.
- Locate the includes/class_core.php file
- Change this line: define('YUI_VERSION', '2.7.0'); // define the YUI version we bundle
To this: define('YUI_VERSION', '2.9.0'); // define the YUI version we bundle
- In admincp go to plugin namager and disable then re-enable a plugin. Theis clears the forum cache
- Test using a fresh incognito browser window