PDF Conversion of file types(.numbers,.pages,.key) are blank

File types like .numbers, .pages and .key are tried to convert to PDF but the end output pdf is completely blank pages. Please let me know why this is happening and how to rectify this issue. Also these files(.numbers, .pages, .key) are created from MAC OS.
MAC OS Version: 10.13
LO Version: LibreOffice 5.3.6.1 30(Build:1)

Your question is tagged common but in fact you are obviously using a single component. Which one? Writer (document), Calc (spreadsheet) or Impress (presentation)?

Edit your question to provide more details (see these guidelines). Describe your procedure (what you do and what you expect). Mention OS and LO version.

Don’t use an answer for this supplementary information, the edit link below the question is done for that.

Thanks for your response.

I’m using Writer (document).
MAC OS Version: 10.13
Can you please give the abbreviation of LO?

LO = LibreOffice, sorry.

Describe your proceudre: what files you take as input, how you feed them into Writer, which command you execute, etc.

File types Involved : .numbers, .key, .pages
Input File: .numbers
Output Required: Number file data in pdf format
Command Executed : soffice --headless --convert-to pdf ‘…/uploads/Personal_Budget.numbers’ --outdir ‘…/uploads’
End Output: PDF file with blank pages

LO Version Used: LibreOffice 5.3.6.1 30(Build:1)

To the best of my knowledge, these formats are not understood by LO. You should use the original application to print to PDF. If this is not possible, try to export in a managed format: the most basic being CSV for spreadsheet and RTF for text document. I don’t know for presentation. An intermediate solution is to use Microsoft formats. In any case, basic or intermediate, be prepared for formatting and data loss. So check carefully the result.

Apple Pages and Numbers partial support ('09 and older) was announced in v.5.0. The same release notes mention improvements in Keynote support. I don’t know its current status, but you are welcome to file bugs with attached sample files that open blank in LibreOffice. Thanks!

By the way, it doesn’t make sense to test with such an old LO version as 5.3. Current is 6.2/6.3, so you should try these first prior to filing bug reports. It could happen that the problem is absent there.

AFAIK, Pages files are packaged files which can be unpacked by any “zip” utility. Older versions used to have a PDF version of the complete document, easily extracted without the pages app, but current versions of pages, as I understand it, inserts only a jpeg image (filename “preview.jpg” or something like that).

Not sure whether there is an image for all pages or only one for the first page. Also I don’t know whether this workaround is viable for Keynote or Numbers, nor do I know whether any of those images is of a quality which represents a credible version of the original document.

You stated that you are working on a Mac, so you should have the option to install the applications from App Store (I believe they are all free for legitimate users of MacOS, but I may be mistaken).

Based on my experience with Apple software, I suspect that running a batch conversion by their apps is significantly less likely to succeed than it is with LibreOffice. Multiple files may be a problem.