Wordpress plugin doesn't subscribe

[Kristiane]

I'm just creating my wordpress website: SourceYourLife.net
I uploaded your widget and installed it. Then I tried to subscribe myself and something doesn't work. Please help me by telling me what I've done wrong or what to change. See screen pictures below of the process or try it yourself.

 

[stanbusk]

Are you sure you have installed MLM properly? You get a server error 404, page not found.

 

[Kristiane]

Thanks, I found the problem.