Why do I get a “. not nullable field error” when attempting to split a feature?

Question

I'm trying to split feature, by point, into 2 new features.

 var pFeatureEdit = lineToSplit.Feature as IFeatureEdit;
 var set = pFeatureEdit.Split(point);

When this feature has configured relation, I got exception.

Got next COM error: The field is not nullable [FIELDID] Where FIELDID - not nullable foreign key in database

Anybody know how to solve this issue?

UPD. When I split this feature using standard Split Tool in ArcMap - it splits successfully. This uses another method to split features?

Answer 1

Based on your comment I am pretty sure you are using ArcVIew license (or basic in 10.1). As a result you are running into a licensing restriction - you can't edit features and geometry of feature classes that participate in a relationship under a basic license.

Quoting; "you cannot edit data from connections to ArcSDE geodatabases, feature classes that participate in geometric networks or geodatabase topologies, feature-linked annotation, relationship classes, dimension feature classes, or parcel fabric layers. If you need to create or edit these types of data, you should upgrade your ArcGIS license to ArcEditor or ArcInfo."

Source: About Edit Sessions

Answer 2

Is the field property 'Allow NULL values' for the field in question set to 'No'? If it isn't a licencing issue, as Jakub suggests, this would be the first thing I check.