Q: Missing Firefox Developer Edition Icon Why is the icon for my Firefox Developer Edition browser missing from my latest version of Ubuntu?


A: The reason that your icon is missing is because the icon file cannot be found. The icon for an application is specified in the .desktop launcher file of the applications, through the desktop entry key icon=. On that line, one can specify a full pathname to a specific icon file, e.g. icon=/home/user/images/firefox-dev.png. Alternatively, one can specify just a file name, without extension, e.g. icon=firefox-dev. Then, the system will find a matching icon file of type xpm, png or jpg searching through your ~/.local/share/icons and ~/.icons folders, and then through icon folders existing under the folders listed in the XDG_DATA_DIRS environmental variable.
Since you installed this application manually, you took it upon yourself to have this right. Thus, make sure the icon mentioned in the .desktop launcher matches a file on your system as I outlined in the first paragraph.

A: You need to point the icon path in your .desktop:
e.g. mine:
Note that I have it installed in /home/jorgee/Applications/firefox-dev/
root@jorgee:/usr/share/applications# cat Firefox\ Developer\ Edition.desktop 

[Desktop Entry]
Version=1.0
Name=Firefox Developer Edition
GenericName=Firefox Developer Edition
Keywords=Internet;WWW;Browser;Web;Explorer
Exec=/home/jorgee/Applications/firefox-dev/firefox-bin %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=/home/jorgee/Applications/firefox-dev/browser/chrome/icons/default/default128.png
Categories=GNOME;GTK;Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
StartupNotify=true
Actions=new-window;new-private-window;
StartupWMClass=firefox-aurora

[Desktop Action new-window]
Name=Open a New Window
Exec=/home/jorgee/Applications/firefox-dev/firefox-bin -new-window
[Desktop Action new-private-window]
Name=Open a New Private Window
Exec=/home/jorgee/Applications/firefox-dev/firefox-bin -private-window

