Hi Carole_Rodgers, and welcome to the forums.
Have you checked that the names of your pictures exactly match the filenames you’ve used in your code? Capitalisation and extension must be exactly the same. e.g. If you call a file picture.jpg, but refer to it in your code as picture.jpeg, it won’t work.
If you’re sure it’s not something like that, then please post the relevant section of your code here, so we can have a look and see what’s going awry.
(If you need help posting code, try this: Forum Posting Basics - #6 by James_Hibbard)