What's fixed
Older versions of the installer could write the soil layers into a map more than once if you ran it several times. Those duplicate layer entries corrupt the map (reported in #23).
v1.4.1 repairs it automatically. When the installer sees duplicated soil layers, it rebuilds the map's i3d from the clean backup it made on the first run, leaving exactly one set of layers. Just run the installer again on the affected map.
One requirement: the original .backup_soilinstaller file must still be next to your map. If it was deleted, reinstall the map fresh from its mod zip, then run the installer once.
Install
Download FS25_SoilLayerInstaller.exe below and run it.