I'm familiar with the issue with Chrome/Adobe compatibility. We've been telling users to download our new XFA form because it won't display properly in Chrome. We're used to seeing "please wait" on the attachment thumbnail.
Today I received an email from a user with the XFA form attached ... but the thumbnail displays properly! When I download the form and open it, it's still dynamic and everything looks like every other version anyone has saved.
I changed some fields on the version that displayed properly as the thumbnail and saved it with a new name. Attached it to an email back to myself. THAT form does NOT display properly -- we're back to "please wait."
I've never seen an XFA form display properly in Chrome -- any ideas why this one did (and how I can make it happen again so we can eliminate this issue for users?)?
The "Please wait…" is the shell pdf that contains your dynamic XFA form contents. PDF viewers that do not support XFA technology – as the Chrome PDF plugin – will only display this shell pdf. To display the entire form you'll have to open the file with an XFA-compatible PDF viewer such as Adobe Acrobat Reader.
Chrome used the Adobe PDF plugin "before" ... I know there have been changes, but why would a form display "please wait," then saved by a user display a proper thumbnail, and then saved by another user display "please wait" again in the span of a few minutes?
I have Adobe Acrobat DC set as my default PDF viewer.
XFA forms do not store thumbnail images as classic PDFs. Even the preview machanism of the Windows Explorer only sees the shell PDF. The contents of an dynamic form are only rendered at runtime by the PDF viewer. It's more like a website stored in a PDF: The PDF file itself only carries the template — which is just a bunch of XML files. Only the PDF viewer that supports XFA creates the layout and all those dynamic things from the embedded XML files when the form is opened.