flash uploader for nextgen gallery is not working since 3.9.1 upgrade

Help! The flash uploader for Nextgen gallery plugin is not working since 3.9.1 WordPress upgrade. I have tried turning off all plugins, re-installing the plugin, checked on Safari, Firefox, Chrome, all with different user roles, and nothing is working. It was working perfectly before i upgraded to 3.9.1 The basic uploader does work, and I can upload via the FTP but can’t use the flash uploader, which is by far the more efficient workflow for my team of editors to upload galleries. Help anyone? Would really like to fix this!