For me as casual user of office programs, it was tough to find out why a document created by a colleague had the layout broken (different line breaks) at some places when I opened it on my PC. It turned out my systems didn't have a required font installed. I suggest LibreOffice should check this when opening a document and warn about it. Otherwise most users will not find out and perceive this as LO bug. The document was last edited and saved on a Mac with LO 3.6.3 with the fonts installed. Opening it on another Mac with LO 3.6.3 and on Ubuntu with LO 3.5.4.2 didn't show any warning.
*** This bug has been marked as a duplicate of bug 44376 ***