Created attachment 132486 [details] side panel artefacts, kde4 VCL plugin Ubuntu 16.04, KDE 5.9 Neon, Tried Libreoffice 5.3.1 from PPA and 5.3.3 Nigtly build. When using KDE4 VCL plugin, there are many artefacts in the side panel, please see attached screenshots. There are no problems with gtk2 and gtk3 VCL engines (but thy do not use KDE native file dialog). It appeared in 5.3.1 or 5.3.0.
The issue is not present in Libreoffice 5.1.6 (from Ubuntu Xenial repositories).
Created attachment 132487 [details] artefacts (kde4), screen 2
Created attachment 132488 [details] normal side panel with GTK3 VCL plugin
*** This bug has been marked as a duplicate of bug 103676 ***