Just for reference for the mods to read, I am also unable to upload images [on Firefox] and both preview attempts and upload attempts send me to a blank white page.
No error messages to tell me what I have done wrong, or which of the two images don't comply to site requirements, just a blank white page.
I have always made my images and thumbnails, 1200 x 800 and 300 x 200. I don't mind making thumbnails and assumed my images were small enough to comply with requirements.
For now, I will be patient until the IT folks have time to work through all the problems. Thank you.