No, I didn't just drag the folder elsewhere (and I doubt I could move a 7GB folder without noticing). I know this because first off, I checked. Secondly, I had a readme file from something else inside my Runtime folder that was still there; it was only the files in the folders inside the Runtime folder that got replaced. So it must have been an error or a virus or something. I'm just glad it seems to be back to normal now.