I experienced similar issues in 2016 and 2017 but at the moment this just happened to me 4 times in a row with my only solution at the moment being relaunching the entire program.
My issue is that after clicking the undo button I am unable to select vertices, specifically when zoomed in. When I zoom out I can select any vertices and on other models I can select vertices as normal, but for some reason for this model after clicking the undo button I am unable to select anything. Relaunching the program 5 times is not making me very happy as you can imagine and from what I can tell I have not pressed anything other than undo that may have caused this, especially since everything else (other model selection, edge selection etc.) works perfectly fine.
Any solutions?
Edit: I managed to temporarily fix the issue by deleting my turbosmooth layer, adding an edit poly modifier, collapsing, saving, closing and reopening the programme. However the same issue presented itself when readding the turbosmooth and then removing it after. I never even pressed the undo button this time, so it could be switching from the turbosmooth layer back to the editable poly modifier that is causing the issue. Honestly, a bit of a joke at this point not going to lie.
