Export Outliner Contents as CVS is greyed out, cannot use

I have used this function before, but today when I try to Export Outliner Contents as CVS, that line is greyed out, and I cannot select it.
I did do an upgrade in June to version 1.9.8.0 for Windows, so wondering if that is the problem? Or am I doing something wrong? I don’t use this often.
thanks
Danny