Could not find any icons after a reboot

Hello,

I know, you said that is not the plank bug, but i want to know whether there is a workaround. If i change an icon theme on my kde machine, plank uses the new icons, but after a reboot he could not find them anymore.

[DEBUG 08:29:30.070089] [Unity:164] Initalizing LauncherEntry support
[INFO 08:29:30.070445] [HideManager:618] Barriers enabled (XInput 2.3 support)
[DEBUG 08:29:30.070543] [PositionManager:677] Without draw_values there is trouble ahead
[DEBUG 08:29:30.074349] [Unity:133] com.canonical.Unity acquired
[INFO 08:29:30.081539] [DrawingService:277] Could not find icon 'system-file-manager'
[INFO 08:29:30.085376] [DrawingService:277] Could not find icon 'preferences-system'
[INFO 08:29:30.087171] [DrawingService:277] Could not find icon 'utilities-terminal'
[INFO 08:29:30.094668] [DockRenderer:491] Cairo.SurfaceType: XLIB
[WARN 08:31:27.412538] Failed to fetch xids: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: Keine derartige Schnittstelle »org.ayatana.bamf.application« des Objekts im Pfad /org/ayatana/bamf/application/1439771161
[WARN 08:31:27.412672] [WindowControl:147] plank_window_control_get_num_windows: runtime check failed: (_tmp2_ != NULL)