What happened to Spotlight and Finder Preview?

Under Yosemite, some docx files saved under LibreOffice Writer show the preview as do all PDF files, but some docx files just show the name and an icon. Using

Is there some add-in that needs to be included?

I love LibreOffice, but there are a lot of docx files from work that I have to use and access.

Any suggestions?

Thank you.