imagesupload folder permissions
I did what you suggested and it broke the functionality of that page completely. I could not get it to work even when I overwrote the Products_Update.php with the original file.
I went looking in the file manager on the server to check out the permissions and the code above must have changed the permissions on the entire imagesupload folder. I manually changed it to 2755 to match the others and now the original Products_Update.php page, with no modifications, works fine for updating the product images.
I am not sure why it's working now unless the imagesupload directory permissions were altered when I got the SSL certificate installed (or by some other unknown means) and now that I have changed them back all is well.
I do hope this is the end of the problem. it may have been the permissions on the whole directory that was causing the problem?