Ok, I think I see,
The location for astrometry.net is not the one which is expected.
Normally, you should set nothing there unless you want to point to a folder where you have built yourself from the sources.
In beta2, there was a bug, meaning we were searching first the default install location (%localappdata%/cygwin_ansvr) before searching the user-defined path. In your case, it was therefore finding the right location, and ignoring your specified path.
In rc1, the bug has been fixed. So now, the fact that you are specifying a folder is taken into account. But it’s not the correct one (should still be %localappdata%/cygwin_ansvr).
Normally, you should therefore leave the path empty in the preferences. But I realize, the UI does not have a button to empty the path. I’ll fix that. For now, just make it point to %localappdata%/cygwin_ansvr and it should work.
I’ll try to see if I can include more thorough testing/console-logging for final release.