Hi Gerd, To build Mkgmap with the PrecompSeaGenerator additional dependecies are needed, like geotools. Currently (r4565) Mkgmap won't build because the location of geotools has been changed, see: http://geotoolsnews.blogspot.com/2020/04/change-to-maven-repositories.html?m... To fix this, update in ivysettings.xml the following line from: <ibiblio name="geotools-resolver" m2compatible="true" root="http://download.osgeo.org/webdav/geotools/" /> To: <ibiblio name="geotools-resolver" m2compatible="true" root="https://repo.osgeo.org/repository/release/" /> Thanks! Regards, Lambertus