first (and unrelated):

i would never use an image name with spaces in it. i would use hyphens instead....

i am not sure what happened on your site, but it does NOT strike me as IH4 related. nor does changing your PHP version to 7 and then back to 5.6.

the question is what happened to your images directory? did you (or someone else) accidentally (or otherwise) delete it? did it accidentally get moved? did the permissions get changed? i'm looking at a hoodie and the image file is:

/images/hoodie%20both.jpg

assuming that file is still on your file system, you would need to find it, and then perhaps we can see what is wrong.

you may have to ask the host for the latest backup if you cannot find the images directory.

good luck!