why is a complete, closed libreoffice writer document slow to open? [closed]

edit

Thank you so much for your help. I've been creating my documents by writing them myself with regular fonts or by copying and pasting articles of interest that I see on-line. They all seem to be affected. I might have to save what I deem important or new since my last wipe-and-install, and then revert to an early restore point. I do appreciate your insight. Maybe it's odd characters or embedded scripts or something that's causing this.

Thanks for your reply. My reply referred to embedding by choosing File > Properties > Font, and marking the box “Embed fonts in the document” which I hope helps when sending editable documents to MS Word users. I then remove the mark and resave the .odt file. For website articles I select the pasted text, use “Clear direct formatting”, then Find & Replace (Ctrl+H) to change all website styles to LO ones. Then I feel more in control. But it would take a real expert to say if I am right.