Hi Alexander,
I moved to new version 26.5 and here my results:
Please see:
Test data(input/output/QGIS)
5363-Gml Esrijson.zip (57.0 KB)
Thanks,...Bug 5363: Gml to EsriJson- Conversion succeeded, output in QGIS-...(gml3.gml) is incorrect for conversion. No root element declaration...