MS Office Word/Excel

In 2019, is this still an issue in opening LO composed and saved docx/xlsx files in MS Office?
I have recently consistently had people advise they cannot open documents saved in these formats when composed, re-saved on LO.

You can enter detailed bug reports on a definite situation on Bugzilla.

In any year, it is quite possible and likely to run into troubles caused by incompatibilities when working with non-native document formats in any application. E.g., LibreOffice might not save some information (e.g., formatting) to DOCX, because of format deficiency; or because of missing support (“not implemented yet”); or because of bugs… Likewise, if you try to save ODF from MS Office, you will get funny documents with all kinds of missing stuff and errors of implementations. You need to keep that in mind when using any application, and try to work with native formats in your everyday work, and only export to foreign formats when need to send something to other parties who can’t use your native formats (it’s 2019, and MS Word can’t correctly read ODF, which support it has declared since Office 2007 SP2)…

Please note that in case of any such problem, it’s good to file bug reports with nice description of a specific problem, and detailed steps to reproduce (including test documents if needed). These bugs allow to gradually improve compatibility over time.

@mikekaganski, i have attached a summary of your description to a page of the FAQ. I have done this because these questions repeatedly come back in similar form.
I hope it is also in your interest.

@Hrbrgr: it’s great that you keep populating FAQ articles; thanks!

Do users suffering from still bad/unusable support for ODF by MS also complain to the respective sites (if existing) run by the “vendor”. Everybody expects LibreOffice to worry about compatibility. Why shouldn’t those harvesting the money do?
Well, I feel to know the answer: Incompatibility is the raison d’etre of commercial software. Thus we need to make LibreOffice the clearly better solution and to advertise that including the then vaild claim that compatibility no longer is a relevant issue…