I am using ArchLinux-x64 The error occurs with LibreOffice Fresh 7.4.2-1 LibreOffice Still 7.3.6-1 Openoffice-bin 4.1.13 from AUR works fine. Editing/Saving a text-file with a normal editor (featherpad) woks fine. Copying/moving files to the mounted storage works fine.
DE is LXQT. Also FireFox has the same problem. So I guess its not the fault of LibreOffice. Sorry!