I’m using LibreOffice 6.3 on Ubuntu 16.04. Last night I noticed a problem with a writer document .odt after I saved it. I closed LibreOffice, then went to open the file and it was empty. On my filesystem is appears as an empty text file (even with the odt extension). Then, this morning, when I wanted to access another document I had been working on last night, I find it too is now empty. Could LibreOffice being doing this? (My files are stored in the cloud and I work directly on them, so perhaps the problem is with the cloud storage - although I’ve never encountered such a problem before).