When I open a .odt files with libre in ubuntu all i see is page after page of ############# what is wrong. the files where made in windows 7 bu t when i did debian a few years ago i had no problem with windows files
Sometimes an issue saving in a pen without extract it properly, files lost.
have you tried opening in a zip archive viewer (can just add .zip to end in Windows)? Inside look at content.xml. That will tell you if there is anything to recover.