Newbie here, sorry if I missed something obvious:
I’ve managed to create an abstract class with abstract methods correctly. But when I attempt to make an abstract attribute on the same class, the “Abstract” checkbox is greyed out in the “Attribute Specification” window so I can’t seem to do it.
Note that I have made the class abstract by selecting “Model Element Properties” > “Abstract” and this allows me to create abstract methods as expected, just not abstract properties.
What am I doing wrong?