ArcGIS Runtime SDK for .NET editing methods execute unexpectedly when using a Named User license with a Viewer level account and an ArcGIS Runtime Lite license together.
This issue is not reproducible in latest version of ArcGIS Maps SDK for .NET 200.5. It is recommended to upgrade to the latest version of ArcGIS Maps SDK for .NET version 200.5. To see what is new in the latest version of ArcGIS Runtime SDK for .NET, refer to https://developers.arcgis.com/net/release-notes.