They're just gone. Plain and simple. I'm working in LR5.6, and I've never had an issue.
My "Save Presets with Catalog" is unchecked. When I click the button to take me to my presets, I look in the Develop presets folder, and it's empty. I search Finder, and I come up with nothing. It's like someone trashed them, but nobody did...
Can someone please help me? Those presets are invaluable to me, and it would take me ages to build them up again.
Thank you!