Hi, im having the same problems as well. it used to work fine, until i tried to change the replace urls settings, and my web suddenly got 500 internal error server. When i try to create a new empty htaccess file, it works, but as soon as i refresh, the 500 error came back again. So the only solution to restore the site is removing the plugin (or rename), but thats not the point. I need this plugin to work again, and still cannot solve the error since then.