MacBook has stopped displaying thumbnails
I have no idea why, but suddenly my MacBook is refusing to show thumbnails. Any files created before the 17th of Feb are fine and all display with thumbnails. Any new files created after the 17th of Feb just have an icon. It's really frustrating and is preventing me from getting anything done quickly as I cannot find the files I need without opening each one.
I've checked the "view -> Show view Options -> show icon preview" and it is ticked. I tried unticking it reticking, but that didn't work. It only changed the files from before the 17th of Feb...
It's really frustrating, and I don't know how to fix it!
Can anyone help?
MacBook Pro 17″, macOS 10.12