Hi Alexander,
I moved to new version 26.5 and here my results:
Please see:
Test data(input/output/QGIS)
5400 Gml GeoPackage.zip (94.5 KB)
Thanks,...5400: Gml to GeoPackage- Conversion succeeded, output in QGIS...screenshot. I understand that the conversion from GML to GeoPackage finishes...