Update to the post. Save Changes does not work on any of the admin pages. Tried disabling Quick Cache to see if it was causing issues with HTTPS plugin, not able to save change on this plugin either… It does work when HTTPS plugin is disabled.
From your post, I think we had a similar issue after loading HTTPS on WP version 3.4.1, upgrading WP to 3.4.2 resolved the issue. I just posted another issues where making changes to HTTPS setting, Save Changes does not work. Hope this is helpful…