When attempting to delete a custom column, a validation error is generated.
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The custom column cannot be deleted because it is currently being referenced somewhere within your LMS instance.
For example, if you are trying to delete an Item Custom Column then you will need to check all active and inactive Items to determine if the custom column is still in use. Check any relevant Connector and Assignment Profile configuration as custom columns can be used in both these locations also.
If still unsuccessful, it could be that the record has interacted with others in the database which has built a chain of relationships in the database structure. Therefore due to referential integrity constraints, the value cannot be deleted.
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