Unfortunately, the plugin does not seem to work with LJ itself anymore. However, it is easy to modify it, so that it works with other LJ-based web sites, such as dreamwidth. In turn, dreamwidth supports fully functioning import from LJ. I have modified the plugin to support thrid-party LJ-based sites, and you can use it to import from, for example, dreamwidth. Since I haven't understood, how to commit my changes here, I have made a modified plugin available on my github. Please google for "github asapegin livejournal-importer" (links are not allowed in the reviews).

Trying to start import, but plugin cannot login to my LJ, and does not import anything.

Import completed successfully on 20 posts. But comments are duplicated for 10 or more times. 🙁