Why aren't new programs showing up in the KDE menu?

Question

I have run into a very odd problem in Kubuntu 12.10. Whenever I add a program through Muon or `apt-get`, it doesn't show up in the menu. For example, I installed Opera from a deb package and Code::Blocks from the repositories, and neither of them are in the menu. I can open them from the command line.

I opened KMenuEdit, and they weren't there. I tries adding them, but when I pressed save, it said it was updating the configuration. Whenever the progress bar reached 90%, it reset to 0%. Here is the output in the termnal:

kmenuedit(18316)/kdecore (services) KServicePrivate::init: The desktop entry file  "/home/andrew/.local/share/applications/Opera.desktop"  has Type= "Application"  but no Exec line 

Could not resolve property : pattern6664
Could not resolve property : linearGradient4636
Could not resolve property : linearGradient4592
Could not resolve property : linearGradient4247
Could not resolve property : linearGradient11897
Could not resolve property : linearGradient11897
couldn't create image from  "" 
Could not resolve property : linearGradient5167

If I view Opera.desktop, the exec line is Exec=opera.

I am using KDE 4.9.5 from the kubuntu-ppa/ppa repository.

Edit

My /home/andrew/.local/share/applications/Opera.desktop looks like this:

[Desktop Entry]
Comment=
Exec=opera
GenericName=Web Browser
Icon=opera-browser
Name=Opera
NoDisplay=false
Path[$e]=
StartupNotify=true
Terminal=0
TerminalOptions=
Type=Application
X-KDE-SubstituteUID=false
X-KDE-Username=

and my /usr/share/applications/opera-browser.desktop looks like this:

[Desktop Entry]
Type=Application
Version=1.0
Name=Opera
GenericName=Web browser
GenericName[bs]=Web preglednik
GenericName[de]=Web-Browser
GenericName[eo]=TTT-rigardilo
GenericName[es]=Navegador web
GenericName[et]=Veebibrauser
GenericName[eu]=Web arakatzailea
GenericName[fi]=WWW-selain
GenericName[fr]=Un navigateur web
GenericName[is]=Vafri
GenericName[it]=Browser Web
GenericName[nb]=Nettleser
GenericName[nl]=webbrowser
GenericName[nn]=Nettlesar
GenericName[pt]=Navegador Web
GenericName[pt_BR]=Navegador
GenericName[ro]=Navigator de web
GenericName[ru]=Веб-браузер
GenericName[sl]=Spletni brskalnik
GenericName[ven]=Buronza ya Webu
GenericName[xh]=Umkhangeli Zincwadi Zokubhaliweyo
GenericName[zu]=Umkhangeli zincwadi we Web
Comment=Fast and secure web browser and Internet suite
Icon=opera-browser
TryExec=/usr/bin/opera
Exec=/usr/bin/opera %U
Terminal=false
MimeType=text/html;text/xml;application/xhtml+xml;text/vnd.wap.wml;text/wml;application/x-mimearchive;application/mime;application/xml;application/rss+xml;application/rdf+xml;image/svg+xml;application/x-opera-extension;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/mailto;video/ogg;audio/ogg;video/webm;image/webp;
Categories=Network;WebBrowser;
StartupNotify=true
X-AppInstall-Package=opera

Answer 1

Edit: On further reflection, I'm quoting partly from the first line of code you provided:

The desktop entry file  "/home/andrew/.local/share/applications/Opera.desktop"  has Type= "Application"  but no Exec line  

It looks like you maybe having two opera.desktop files: one in ~/.local/share/applications and the other in /usr/share/applications. My understanding is that the first takes precedence but it's possible some weird confusion may be occurring?

---

Please look at Opera.desktop again. See if you find a line, or lines, like this:

OnlyShowIn=Unity

A list of other OnlyShowIn= options is here.

If there is such a line, open Opera.desktop with a text editor (and sudo) and comment out that line by adding #. Save the file. You may now see Opera in your menu.

You can read more on the subject here. The "opposite" of OnlyShowIn= is NotShowIn= and if there's a line like NotShowIn=KDE that could be to blame.

And you may need to refresh things by running

sudo update-desktop-database

according to this answer.

Of course, it's entirely possible that there's some other solution altogether!