did you ever run into invisible or super small vertecies in 3dsmax?
here is what you do:
1. try to increase/decrease vertex size in:
customize->preferences->viewports->show vertecies as dots->size
2. if this wont help, go find your computer screen resolution dialog and change the color depth to another setting and then do not accept or revert to your old setting.
this will basically reset your graphic card driver and your vertecies will be visible again!