Hello, kendoori.
Just today, I experienced the same problem as you reported, no matter whether I tried to launch a Java application through a .JNLP file using Firefox 3.6.16, Firefox 4.0 or Opera 11.01. I kept on receiving the same kind of error message that you reported > /tmp/play-1.jnlp could not be opened, because an unknown error occurred. Try saving to disk first and then opening the file.Even if I did save the .JNLP file to disk, right clicked it in Nautilus and selected to open it using "Sun Java 6 Web Start", this did not work and I recceived an error message stating that "the file" could not be found. No detail given which file might be "the file".
[U]Environment here: [/U]Ubunto 10.04, 32-bit Firefox 3.6.16 (Ubuntu build), Firefox 4.0 (Mozilla build), Opera 11.01 Oracle Java 6 Update 24
[U]Default action defined in [/U]
[U]Note: [/U]Launching .JNLP files in Nautilus and the browsers had still worked a few weeks ago.
- Nautilus: Open in "Sun Java 6 Web Start"
- Firefox / Opera: Open in "Sun Java 6 Web Start (Default)"
[U]Investigation steps: [/U]OK, I'll cut those short and report the results only: Google is my friend. So are the Ubuntu help and forum pages. :D
_Source of trouble:_
The Gnome desktop defines the actions which will be performed on file types in a file named mimeapps.list, located in the folder ~/.local/share/applications.
grep jnlp mimeapps.list
application/x-java-jnlp-file=sun-java6-javaws.desktop
~/.local/share/applications$ cat sun-java6-javaws.desktop
#!/usr/bin/env xdg-open
[Desktop Entry]
Encoding=UTF-8
Name=Sun Java 6 Web Start
Comment=Sun Java 6 Web Start
Exec=/usr/lib/jvm/java-6-sun-1.6.0.22/jre/bin/javaws %u
Terminal=false
Type=Application
Icon=sun-java6
Categories=Application;Network;
MimeType=application/x-java-jnlp-file;
This line still references the no longer existing Java 6_22 version. So the line should read: Exec=/usr/lib/jvm/java-6-sun-1.6.0.24/jre/bin/javaws %u or even better to prevent the same error from re-occurring after the next Java update: [B]Exec=/usr/bin/javaws %u
[/B]_Solution:_ Modified the file sun-java6-javaws.desktop to read ``` #!/usr/bin/env xdg-open
[Desktop Entry] Encoding=UTF-8 Name=Sun Java 6 Web Start Comment=Sun Java 6 Web Start Exec=/usr/bin/javaws %u Terminal=false Type=Application Icon=sun-java6 Categories=Application;Network; MimeType=application/x-java-jnlp-file;
[/U]Launched Firefox and downloaded the .JNLP file to disk. Right clicked it in Nautilus and selected "Open with Sun Java 6 Web Start". The application was launched without problems.
Launched Firefox and selected to have Firefox to "Open with Sun Java 6 Web Start (Default)". The application was launched without problems.
[U]Status:
[/U]Problem solved.
HTH,
Karl