It's very strange you got the Japanese language setting, sorry about that! We don't use IP addresses to guess the language. It works like this:
If you go to a specific language like zh.esotericsoftware.com then you'll get that language. If you go to esotericsoftware.com you'll get the language the site has stored in a cookie. If there is no cookie (it's your first visit or you've never explicitly chosen a language), then we use the Accept-Language HTTP header that your browser sends. The only thing I can think is that your browser told us to use Japanese. We'll do some testing and make sure it is all working right.
As for your inability to run Spine, as the link Erika shared explains, the first thing is to look at your spine.log. Likely something from in there would help us determine the problem. It's also good to disable antivirus or anti-malware software that may interfere with Spine.
