Was due to oldish settings (empty file) into .local/share/applications/....desktop conflicting with the now used /usr/share/applications/....desktop
Purging these empty .desktop files inside .local/share/.... have stopped these errors. ** Changed in: gnome-panel (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-panel in Ubuntu. https://bugs.launchpad.net/bugs/1132130 Title: gnome-panel: Unable to parse mouse modifier '(null)' Status in “gnome-panel” package in Ubuntu: Fix Released Bug description: get that error on each login as gnome-classic (fallback) on RR i386 , and the drag & drop does not work at all, nor selecting part of a sentence. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: gnome-panel 1:3.6.2-0ubuntu3 ProcVersionSignature: Ubuntu 3.8.0-7.15-generic 3.8.0 Uname: Linux 3.8.0-7-generic i686 NonfreeKernelModules: nvidia ApportVersion: 2.8-0ubuntu4 Architecture: i386 Date: Sat Feb 23 15:35:57 2013 ExecutablePath: /usr/bin/gnome-panel GsettingsChanges: MarkForUpload: True SourcePackage: gnome-panel UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-panel/+bug/1132130/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp