Links not working for Debian Buster XFCE (Firefox 78.5.0esr (64-Bit))

[de-ramon]

Hi,
I just installed the helper app and tested some links like

• file:///media/daten/Test/
• file:///media/daten/Test/test.txt

with the default Firefox 78.5.0esr (64-Bit).

There's no error message (if I try to link to non existing files, there an error message), but nothing happens.

What app should be launched? Regrading to "update-alternatives --get-selections" it should be
x-window-manager auto /usr/bin/xfwm4

Is it possible to get more verbose logging?

thx,
ramon