The issue arises because a new feature class was added to an already versioned feature dataset. In traditional versioning, adding a feature class requires the administrator to first unregister the dataset, add the new class, and then re-register the entire dataset as versioned. The new feature class is not automatically registered. This creates an inconsistent state where the new class is not versioned, preventing edit sessions from starting correctly on the dataset. Re-registering the feature dataset ensures that all its contents, including the newly added feature class, are properly registered for versioned editing, resolving the issue.

A. Connecting as the data owner will not resolve the underlying technical issue, as the dataset is in an inconsistent versioning state. Permissions are not the root cause.

B. Unregistering the feature dataset permanently is a destructive action that would delete all existing versions and their associated edits, leading to significant data loss.

1. Esri ArcGIS Pro Documentation, "Register data as versioned": This document outlines the required workflow for schema changes. It states, "To add or remove a feature class from a feature dataset that participates in traditional versioning, you must first unregister the feature dataset as versioned." This confirms that adding a class requires an unregister/re-register cycle, which the administrator must complete to restore edit functionality.

Source: Esri. (n.d.). Register data as versioned. ArcGIS Pro Documentation. Retrieved from https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/register-data-as-versioned.htm (See the section on "Registering and unregistering feature datasets").

2. Esri ArcGIS Pro Documentation, "Schema locking": This resource explains that exclusive schema locks are required to make changes to a dataset's structure, and these locks cannot be obtained on versioned data. This is the underlying reason why the dataset must be unregistered before adding a feature class.

Source: Esri. (n.d.). Schema locking. ArcGIS Pro Documentation. Retrieved from https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/schema-locking.htm

3. Esri Training, "Deploying and Maintaining a Multiuser Geodatabase (for ArcGIS 10.5)" Courseware: This course covers administrative workflows for enterprise geodatabases. Module 7, "Geodatabase Maintenance," details the procedures for performing schema changes on versioned data, emphasizing the necessity of the unregister-modify-reregister workflow to maintain data integrity and functionality.

Source: Esri Training Courseware, "Deploying and Maintaining a Multiuser Geodatabase," Module 7, "Geodatabase Maintenance," section on "Modifying Versioned Data."