Have any of you found a way to render a PDF file stored in a doc lib on a Nintex Form in Office 365? I've been able to get a solution working for word documents using this thread as a guide (Page Viewer Control - not displaying Office 365 files ) but it doesn't seem to work for PDF files - ends up with the "This content cannot be displayed in a frame..." error message.
Moving on to a different approach (outlined in this blog: How to embed a PDF in a modern SharePoint page) seems very promising but I can't seem to find the secret sauce that doesn't end with the same error message above. Apparently the modern document library experience handles the document preview feature through the views themselves instead of relying on the WopiFrame/WopiFrame2 pages.
That said, I'd challenge you to try simply configuring a page viewer control to show the All Items view of a document library without any. Doesn't work for me but it would be useful to understand why that's failing to possibly shed some light on getting doc previews to work in the page viewer. Anyone found a way to just get a view to render on a Nintex form in Office 365?!
Appreciate the help if anyone has suggestions!