This should not be this difficult. I have a top-level notebook, let's call it Notebook1. I want to nest a notebook underneath it (let's call it SubNotebook1) like I've done multiple times in the past; however, now when I try it I end up with a new notebook called 'Notebook Stack' with both Notebook1 and SubNotebook1 nested underneath. This is a completely useless feature that should be burned with fire. I attempted to right-click SubNotebook1 and select 'Add to stack', but the notebook I want to nest it under does not populate in the resulting window and there is apparently no option to select any other notebook to 'Add to stack' to other than the ones I am presented with. Anyone?