In PRPC 7 ML7 the functionality of Tracking changes on a data instance is broken as the function that writes the history record uses a new property called pyPropertyIndex (which is a String instead of an Integer as you would expect). The property only exists in Embed-ModelParams class and not @baseclass so for an Operator record (Data-Admin-Operator-ID) it would not find it. The operator record is however initially saved. The operator record cannot subsequently be changed as validation fails when it sees this property on the operator top-level page.
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