Firefox 48 beta 10. when i was uploading multiple images for some of my resource/update, the images uploaded got stuck on first image. it showed 100%, the cancel button greyed out and nothing happened. the full image & thumbnail button didn't show even i waited for a few minutes. so i assumed the upload was failed based on what i saw on the throughput in the Task Manager. but however if i uploaded the images one-by-one, the images uploaded successfully. any ideas for this issue?