no open dwg

have: Version: 2.1.2
Compiler: GNU GCC 6.2.0
Erstellt am: Sep 17 2016
Qt Version: 5.9.5
Boost Version: 1.62.0
System: Linux Mint 19.2

If I open dwg I must break this work-it do not work.
What can I do?

dwg-support is to be considered experimental only in LibreCAD, may work or may not. If it doesn't work try converting it with an external tool, like Teigha File Converter, to dxf 2007.