Not list in the drop down menu

Right clicking a Doc. file does not list LibreOffice as an available program. Why?

Windows? Linux? Please be more precise in asking a question.

Can you do it the other way round, ie open LibreOffice and then open the file from the File menu? If you can do that, then you need to fix your file associations.

Assuming you’re running Windows 7:

Assuming you’re running Ubuntu:

There may be others, but there should put you on the right track.