The allowed values for version are:
DwgVersion.AC1014 // R14
DwgVersion.AC1015 // 2000
DwgVersion.AC1800 // 2004
DwgVersion.AC1021 // 2007
DwgVersion.AC1024 // 2010
DwgVersion.AC1027 // 2013
DwgVersion.AC1032 // 2018
DwgVersion.AC1035 // 2021