My message might not be of allot value either (no logs), but I experienced this with a couple of previous downloads too. Unfortunately I can't remember which downloads it were.
AFAIK it only happened on 0.36.0, It were overnight downloads, so I woke up and found my PC still being on unexpected, whilst now, when I'm downloading during daytime, all downloads are finished just as they are supposed to, this is in version 0.36.1.
So it could be the improved RegEx in 0.36.1 that fixed this, or that one of the search engines (in my case Binsearch) was having some issues.
Since all seems fine now for multiple downloads, I don't worry about it anymore.