Some error are being Thrown by custom TargetedTriggerActionT, when the associated element is unloaded ( i think )
I attach a xaml with a sample situation that produces the error, first tab contains a list and a textblock that is using the custom trigger
When clicking second tab, the errors are thrown

I attach the sample implementation being used both header and cpp files.

NOTE: If using TargetName instead of TargetObject="{Binding ElementName=Selector}" the error is not produced.

The equivalent implementation in c# does not produce any error. With any of TargetName or TargetObject