I can confirm @Caterina Trainito's comment - still broken in Confluence 6.15.9 and tbh quite annoying.

Just after the pdf preview component has been added, it works. But subsequent requests start to fail, sometimes only some pages aren't displayed and getting worse over time, sometimes the preview images for all pages in the pdf are not rendered any more with the second request.

The log files just show a 404.

Still broken in Confluence 6.15.1. Deleting the Viewfile plugin cache does not work as a permanent fix.

This has been a problem for a while. I have seen this in sever 5.x versions but our current version is 5.10.4.

Problem still exists in 5.7. I cannot view PDFs in the previewer.

Sorry to open this again; however, we're using Confluence 5.8.15, and I can only find the PDF, Office Excel, Office Powerpoint, and Office Word macros. I don't see anything that looks like 'previewer' or 'file previewer' or any other name that promises to show the content of an attached file.
I'm trying to allow a user to view the contents of an attached PDF file; however, like other users writing comments here, I'm losing portions of the PDF file.
Please advise what macro to use for the 'new file previewer released in Confluence 5.7"

Thanks everyone, for the feedback here. This issue appears to be fixed in the new file previewer released in Confluence 5.7. We are no longer investing in the viewfile macros and all future improvements will be made to the new previewer. Please try it out in the new previewer and if this remains an issue, raise a ticket against that.

Regards,
Natasha Prasad
Confluence Product Manager

Still exists in Confluence 5.6.4, Windows 7 SP1 x64, IE9/Firefox 33.
Thumbnails of PDF files embeeded in Confluence page doesn't display correctly. Not all content of PDF pages is visible.

The same for me with 5.6.3 on Windows Server. The page either shows a blank page or an broken icon.

I understand, thank you. And I've found the Office Connector-option.

To change your install would not effect this bug, therefor just for not be able to display PDF's I'd not change the instance.

As Atlassian is appearently not willing or resource wise able to fix this in a timely manner, I guess we just have to live with that bug that Confluence is not able to display complete PDF files or PPT's.

P.S. Above workaround is not a fix it's a bad user ... "give me at least some little improvement".
Don't know if Office connector Setting has changed sinc 5.4.1 .... to clearify
it's Confluence Admin Menue -> Office Connector -> Option: "System Resource Usage" -> Heading "Temporary storage for viewfile macro:" -> checkbox Cache in-memory: