Gosh, that's odd. No, no problems with Firefox and Windows 10 here.
Does it crash immediately when you launch Firefox, or randomly while you're browsing later?
No, it's to dangerous to put it on Duplicate, sorry. Leave it on Extend, and try making it the main display as I suggesed.
Sure, maybe that would help!
Don't worry about this. As I said, the computer will know.
Sorry, I've tried all the file formats I can think of. Nothing is working.
Brian might have some wiser ideas, but honestly, with the file sizes so small, I fear these files are unusable.
Ah.
Brian will have wiser advice, but in my experience you can have success (sometimes) by changing the filename. Try ".tif" and ".jpg" and even ".psd" to see what happens.
Also, do you mind sending me one or two of the troublesome files? https://spaces.hightail.com/uplink/BellePhotography
Of course don't do ANY Photoshop work until the raw editing is done properly.
PLEASE keep posting photos in the class. You should have been well and truly finished it by now.