I used to be able to save Libre Office Writer files as documents wheih Microsoft Word users could open. Now I can’t.
what LO version do you use? Now when?
From release notes for LO V 7.0:
DOCX now saves in native 2013/2016/2019 mode instead of in 2007 compatibility mode. “This mode is intended to ensure users of different versions of Microsoft Office can continue working together and documents created with older versions of Office won’t look any different when they’re opened in future versions of Office.” So this mainly benefits Word users - where documents can use more features and Word’s bugfixes since DOCX 1.0 can be applied. Although this means Word 2010 users lose out a little, Microsoft has done the same to them since 2013, and it is end-of-life before 7.0 reaches stable status. Word 2010 users should upgrade to LibreOffice. tdf#131304 tdf#123116 tdf#131121 (Justin, SIL; Miklos/Mike, Collabora; Samuel Mehrbrodt, CIB)
Otherwise use .doc. Cheers, Al
The mentioned change should not prevent MS Office 2007-2010 from opening the files, though; it just means that those files may look differently there (if they happen to use features that was changed in later versions).