Any idea how to fix this?
fix the orthography / grammar first, so we can actually understand what your problem really is and last but not least we feel some respect.
How did the script look like where you added your files through a Insert File script step?
Drag and drop physcially copies the data into the container field. This is not the "store by reference" your original post seems to indicate that you've set up. If your script is using a "store by reference" option, the files may well be located in a location not accessible to your users trying to view it. This might be a folder permission setting on the folder storing the images.
Please note that this refers to "store a reference" container images. If you set up external storage, the rules are different.
So as others have noted, you need to take a look at the exact options specified for your script step that inserts the file into the container field.
And what is the value of "$fileParent"?
Does it start with either "imagemac:" or "imagewin:" ?
And you are using the very "by reference" option that I pointed out makes for a difference between when you drag and drop and when you use this script. Drag and drop puts a physical copy of the file into the container field. "by reference" just inserts a file path that allows FileMaker to find and access the file at its current location. If the user does not have permission to open files in that location, they can't see them.
$fileparent is: "image:Files/Product Entry/ExtractedImagesOldSite/"
Hmmm (and I'm a bit of a noob), so how would I change the script ot put a copy of it into the database. Also, would that make my database very large? There are about 14,000 images and then all those images get resized into another container for a website.
Although I've got lots of disc space, a big database isn't the end of the world.
It could make the file very large indeed, but that's what you are doing with drag and drop currently. I suggest that you read up on the external storage option that you can set on the container field, then remove the "by reference" option from your script step after setting up external storage for this container field.