Data source &1 is not a transactional CDS view.

What causes this issue?

The consumption view uses the annotation
ObjectModel.transactionalProcessingDelegated<(>,<)> but the underlying
CDS view is not transactional enabled.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Either add the annotation '@ObjectModel.transactionalProcessingEnabled:
true' to the underlying CDS view or remove the annotation
'@ObjectModel.transactionalProcessingDelegated' from the consumption
view.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.