brent why do you [...] find the gtk icon error insignificant?
Actually, I don't find it insignificant. I thought that perhaps it could be the cause of the issue. But now that tomscharbach has shown his works with the same error (launched from terminal or Kickoff) I think we can eliminate that as a root cause.
Now I suspect what brent theorized earlier: a misconfigured desktop file.
Here are the contents of my desktop file at /usr/share/applications/solus-sc.desktop
:
[Desktop Entry]
Name=Software Center
GenericName=Software Center
Comment=Install, Remove and Update System Software
Exec=/usr/bin/solus-sc
Terminal=false
Type=Application
StartupNotify=true
Icon=system-software-install
Categories=X-GNOME-Settings-Panel;PackageManager;System;Settings
Keywords=Updates;Upgrade;Sources;Repositories;Preferences;Install;Uninstall;Program;Software;App;Store;
Actions=view-updates;
[Desktop Action view-updates]
Name=Updates
Exec=solus-sc --update-view
@BruceElephant if yours doesn't match that, perhaps that is our culprit.