Changes to metadata not saved

Herald of Fire

I'm not sure if this was broken in an update, or whether it's a weird quirk on my own system but I can no longer make any changes to metadata aside from those imported directly through the DIM. Any changes to category I make are ignored, and any thing I try to drag and drop from the Content Library into the Smart Content tab never show up as such.

What's more frustrating is that edits that I had previous made are now undone and I can't even change them back. Any idea what might be causing this nuisance? Has the database magically been switched to a read-only status? I should point out that no error messages come up and the hard drive reads as if i were being saved, even though nothing comes of it.

Any ideas I can try to sort this issue out would be a huge help.