Saved files disappear!

I am using the latest version of Firefox. As I make progress on a sketchup project I save the file. That way, if I screw up I can just reopen the previously saved version. However, the saved files are nowhere to be found! I use different filenames for each one but they do not show on my list of files. Anyone know where they went? Thanks.

you’ll see any ’ Projects’ first, I had already opened one…

john