cant access my photos

Stop worrying.  Worrying causes wrinkles.

It is great that you backed up your vault but you should have copied it to your hard drive not moved it.  Apparently the upgrade updates the vault when it is installed.  Since you had moved the vault the upgrade couldn’t do that.  At this point I don’t know what to tell you.

Try contacting SanDisk and see what they suggest. 

https://kb.sandisk.com/app/answers/list/kw/will%20my%20cruzer%20work%20on%20windows%208%3F/sno/1/search/1/session/L2F2LzEvdGltZS8xMzY2ODI5MzEzL3NpZC9xem4xR3hvbA%3D%3D

http://www.sandisk.com/about-sandisk/contact-us/