Unable to add Column to Visual

When adding calculation groups to a model, Tabular Editor sets the model property DiscourageImplicitMeasures to true, since this is a requirement for calculation groups to work in the first place. In other words, if you want calculation groups in your model, you can't have implicit measures (i.e. adding column aggregations directly to visuals). Instead, you'll need to create explicit measures using DAX.

So if you want to undo this, you'll need to open the model in Tabular Editor once again, delete your calculation groups, and set DiscouargeImplicitMeasures back to false.