Hi,
I was experiencing a similar problem on our page https://www.unfairtobacco.org. After updating the plugin, the login page and all other HTTPS pages were not available anymore. I did not get any error messages, only the pages didn’t load.
Deactivating the plugin via FTP and downgrading to 2.0.4 fixed the problem.
It’s a pity because I thought the update may fix another problem that I got with the page: HTTPS protected pages are not available in English (our page is in German and English). The HTTPS plugin seems to have a conflict with qtranslate or the other way around.
Laura