I'm still receiving 'Connection error, please try again later!" for just about everything I try to download (which, for the moment, is just The Witcher's combined bonus content pack). Only about every other time does the Downloader WER crash while processing the download requests (i.e. while some or all items say 'Preparing...") The most common error messages in the logger say:
"Message: The operation has timed out
Message: Object reference not set to an instance of an object."
Also, why must I download all of the bonus content items at once (in GOG Downloader Mode)? What happened to being able to pick and choose?
No idea about the crashing and the time outs, however, 2 points.
Point 1) The preparing phase is actually the downloader checking the existing files (or parts of) to see what has been downloaded and what hasn't. It really should get a better description.
Point 2) No downloader ever had the option to add only one item of the bonus content to its queue, closest one was downloading through the browser. However, if you truly want only 1 of the files, right click the ones you don't want and remove them from the list.