Serious What am I doing wrong??

I've made a thread about this girl I like from a different country, and got great advice. I've been trying to casually talk to her, but she just all of a sudden doesn't reply. And I know she's still online. Here's an example:http://prntscr.com/8lw8u7 . This just started happening, and it's been happening a lot this past week. My gut feeling is telling me that I've somehow annoyed her and just need to step back. But I want to hear what you guys have to say. Thank you