Opening a File that asks for a Filter

I downloaded an OpenOffice file, but when I try to open it, I'm prompted to select a filter. How do I open this file?

This file may be compressed. Uncompress the file (with a program such as WinZip, Pkzip or other) or untar it using the tar command (on Linux systems) and re-try.

If, after unzipping, the file contains only characters # : it is damaged beyond repair and there is NO content !