At the DXF / DWG export of pages AutoCAD versions that are not supported anymore have been removed in the settings. The two following entries are now available in the drop-down list of the Format version field:

• AutoCAD 2013/2014/2015/2016/2017
• AutoCAD 2018/2019.

(A menu path for the settings dialog is: Options > Settings > User > Interfaces > DXF / DWG export and import; Export tab.)