@fredo6 I get this issue a lot as well with Box tapering. the fat green arrow that won't allow you to do anything to the model.
pic attached.
IMG_3151.jpeg
When you right click the cursor just vanishes, yet leaves the object highlighted.
Is it also correct that you cannot use box taper when you have groups of geometry? I am a set designer and I use the tool all the time in order to play with perspective, however every time I use the tool on a groups within a group its crashes my Mac. A few other designer friends of mine have mentioned that they have the same issue with the extension. It makes doing build plans in Layout really complicated with having to redraw.