I find in several places, notably wiki.documentfoundation.org, the statement that “Calc 3” in both OpenOffice and LibreOffice will open Quattro Pro
Whenever I try to open one, I get an error:
Read-error. Error in file structure while importing.
Thinking perhaps an extension was needed, I searched the extensions catalog for a Quattro Pro extension but found none.
Where am I going wrong?