Great news!
Now if you would like to get back opening the files by double-click then
(on Windows 10) do the following:
- find the file the same way you do to get the message about file:///...
- RIGHT-click the file
- click the "Properties" option at/near the bottom of the menu
- click the "Change..." button that is to the right of "Opens with:"
- click the program, Base, that you will use to open the file
+ if Base isn't an option click the "More apps ↓" link to display more
programs to open the file
+ if Base still isn't in the list then install LibreOffice again
- click the "OK" button
- click the "OK" button
Now double-click the file and it should open in Base
If you're not using Windows 10 the process will be similar whatever
operating system you're using, earlier Windows versions, Mac OS, Linux.
Select the file, show its properties menu, select the menu option for what
program opens the file, select the program to use.