Just had a problem with using Windows Live Writer after the software updated. I went to post a blog to my self-hosted WordPress install and got the error below;
Invalid response document returned from XmlRpc server
I couldn’t work out what it was but found a closed topic on www.wordpress.org that talks about php filenames being wrong.
As I hadn’t had any previous issues and had been using Windows Live Writer fine during the last week I decided to check my plugins were updated. One wasn’t so I updated that even though it wasn’t an active plugin. That didn’t work so I simply went into the dashboard and ‘Updates’. Here I used the ‘Re-install Now’ button to reinstall the WordPress core code and after doing this Windows Live Writer worked again seamlessly.
Update: As a friend pointed out to me – uninstall any inactive plugins. They are a backdoor for hackers.