I have a site which I set up for a client a couple of years ago and has been working fine up until now. The problem is whenever he uploads a new PDF file (other file types seem fine, even larger image files are okay) no thumbnail is generated. This is also breaks the layout of one page on the website. The file uploads ok and I am able to view it though it's direct file path.
GD is enabled but Image Magick is disabled - could this be the issue?