I’ve been having the same problem for several weeks.
@mercime, your suggestion to import a WordPress WXR file will not work, as sadly the 2MB file size limit is way too low for many people facing this problem.
WP has seemingly imported all my posts, but ~100 of my oldest comments are missing. I’ve tried deauthorizing the Google/Blogger account over and over, and reinitiating the import. Once in a while it recognizes a couple more comments, and that’s it, it just quits. Mostly it does nothing, but reports it’s “Done”.
There are around a dozen different threads here with issues like this. I wish someone in the WP community would actually address this import tool error.
