For some reason, there's a few PDF files, which my wife can't print from her PC (most of them she can).
She's now running Windows 10, but when she ran Windows 8, she had the same issue.
It's only happened a few times, but I still find it strange, as I can print the same PDF file with no issues from my Macbook Pro.
The printer we use is an HP Deskjet 1510 (connect via USB).
It's not the end of the world, but I'm still curious why this issue happens.