In a Google image search, I am unable to save certain images via the preview, while others I can save from the preview.
For the ones that don't save, when I right-click the preview and select Save Image As, I can select the destination folder and click Save, yet the image doesn't save and the download is marked as failed in my Firefox browser. I have to click Retry Download to save these images. If I directly view the images I save all of them successfully the first time.
(note that they are similar in size):
This started happening today, and again, only for certain image previews. I tried a different computer with an out of date Ubuntu installed and all images save normally there, so it might be specific to my system.