It looks like once you upload the form, it;s trying to render the view for you, and the tool bars around the page sure make it look like it's an official Adobe Acrobat or Reader plugin that's at work. But we can never be too sure, can you check the browser settings and see if the Adobe plugin is active. the browser's own PDF plugin might not work with XFA based forms. The message you see is pretty common when an XFA based PDF is opened in browser with browser's in built plugin.
Secondly,
Can you do this, : Go back to designer and this time try to save your form as a static PDF, this would still keep your form interactive, just not flowable, if you have fields of that kind. I'm not really from the Echosign team, but i;m pretty sure i've had this working in the past.
I'm not really an Echosign pro, but i found another post discussing similar subject:No XFA Form Support?!