I'm not certain which device you're using, but in my experience, Windows Phone does this. It's similar to what happens when attempting to view a dynamic form from within Chrome's internal PDF viewer. Unfortunately, for Windows Phone 8.1, there's nothing to be done about it.
I have the same issue, I have Samsung Note 3, but cannot see the document, message says your pdf viewer may not be able to display this type of document and then says you can upgrade to latest version of Adobe Reader for windows,Mac or Linux. But Samsung has Google operating system, what do I do?
The "Please wait..." message is the shell PDF every dynamic XFA-forms lives in.
A PDF-viewer that doesn't support XFA technology will only display that message.
The fact is, that there is currently no PDF-viewer for mobile divices which will support XFA, even Adobe's Reader mobile doesn't support it.