The property <property name> cannot be deleted
The selected property is set as the Discriminator Property for the inheritance between the classes indicated in the error message. Properties cannot be deleted if they are participating in the inheritance configuration between data classes.
Set the Discriminator Property to a different property of the data class to enable successful deletion of the desired property.
To correct this error
In the O/R Designer, select the inheritance line that connects the data classes indicated in the error message.
Set the Discriminator Property to a different property.
Try to delete the property again.