UML/SysML: MagicDraw/Cameo 19SP3: GOTCHA/TIP: An Instance Table will not display a row for instances typed by an abstract Class/Block (although one can show such instances as InstanceSpecification symbols on a Class Diagram or Block Definition Diagram)
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This might be consistent with the idea of an abstract Class/Block, but it can make it hard to progressively analyse and debug/test hierarchies with correct abstractions.