Thank you for your message. I am sorry you are having this problem.
I am sorry you are having this problem. When was the last time you saw them there? Have you recently cleared your cache or re-installed the browser?
Unfortunately, if you are using the same browser on the same computer and they are no longer there, they are most likely gone forever. his could happen if, for example, you cleared your cache in the browser, used a utility which cleans your computer, or ran low on disk space (additional possibilities are listed in the first document referenced below).
I said "most" likely, because there are steps you can take to rewind your cache if you had already been backing it up, but most people do not do that. My primary platform is Mac and I back my browser cache up with Time Machine on the Mac, so I can go backwards in time and restore my cache from a point in time. This has saved me a few times when something was deleted from my cache and I was able to roll the cache and settings back a day. If Windows was my primary platform, I could do something similar on it.
For a complete description of existing features to save prompts and images, please see these documents:
Where the cache is located differs depending on which browser you are using. A few general tips:
While you are working on restoring, do not run that browser. Exit it before starting.
When you find the directory you need to restore, do not restore it over the directory as it is now. Move the existing directory off to the side and then restore. For example, if you need to restore the directory "abc", move the existing "abc" directory to something like "abc.old" and then restore "abc". When you are done and it is working you can then delete "abc.old". But if something goes wrong, you can move "abc.old" back to "abc".
Different browsers and versions of them (and different versions of MacOS) store this data in different locations. Documentation on finding the location in Firefox, for example, is here: http://mzl.la/1BAQULj. Depending on which browser you are using, you will need to find where it is storing its cache, so you can restore it.