Hello :)

When the preferred web browser is set to Opera (Menu→Settings→"Xfce4 Settings Manager"→ "Preferred Applications", "Web browser": "Opera browser") and the applications menu is opened (from panel or desktop) and Help is clicked then Opera starts and displays "You tried to access the address http://'file///usr/share/xfce4/doc/C/index.html', which is currently unavailable".

If "file://localhost/usr/share/xfce4/doc/C/index.html" is entered in Opera's address bar and actioned the Xfce4 Help is displayed as expected.

ps showed the command being run was /usr/lib/opera/9.64/opera -remote openURL('file:///usr/share/xfce4/doc/C/index.html',new-window)

Configuring Firefox as the preferred web browser worked around the problem.

This problem seen using Xfce 4.6.1, with Opera 9.64, on ubuntu 8.04.3, without environment variable $BROWSER.

When environment variable $BROWSER was set to opera and the Help request was simulated by running xfhelp4 from a gnome-terminal command line, Opera displayed Help as expected but a second instance of Opera was started, too.

I tried to find a fix but could only get as far as finding that script /usr/bin/xfbrowser4 runs this command:

exo-open --launch WebBrowser file:///usr/share/xfce4/doc/C/index.html

Best

Charles