I have this issue with Libre Write not playing well with my printer. I print this docx fine with Word, but Write mangles it somehow. It is a #6 coin envelope.
I tried customizing it in Write but it was no go 
You can download the .docx here
Thanks a heap!
I would suggest you describe what happens and which printer you’re using, as well as which version of LO and which platform it runs on. Perhaps upload or link to an image of the result.
I’m Using an HP MFC-7840W with the latest drivers. What happens is the areas I have made (address, return address and logo) are printed beyond the boarders of the envelope. I see this if I use a sheet of paper.
Here’s an example. Top one printed in Libre Writer 5.0.2.2, bottom in MS Word:
You went to Format / Page / Page in Writer and checked the page size and adjusted the margins there?
Yes, I fiddled with it in Writer for hours but it still wouldn’t work. I even tried making a new one from scratch, no go 
It is always a good idea to save foreign file formats (.docx, doc, xls ) as Open Documents (.odt, .ods). These are the native formats for LibreOffice and work with them.
Also Word 2010 and 2013 can read .ODT documents. Word2010 complains abit but I never had problems.
