As an FYI to others who might encounter this issue:
We had a working QlikView application deployed on our Access Point. The appropriate users could access it correctly, but it would not generate a preview. We got the QlikView logo with "No Preview Available".
We had Webview turned on (in QlikView) when we saved the application. When I unclicked Webview and resaved the app, the preview generated without a problem.
I do not know if this is common knowledge; I had posted a question about it, but I cannot find that discussion (?).
TL/DR version: Turn off WebView before you publish your QlikView applications.