Slicing Tolerance 'Exclusive' won't slice, but middle and inclusive do?

[milehigh3dii 0]

Running 3.1.0 on a MBP with Sierra 10.12.6.  Cura has some odd behavior.  I wanted to try the Slicing Tolerance setting to try to get screw holes and nut recesses to print better.  I enabled the function, and it will say that is slicing, but with the 'exclusive' setting it the bar goes all the way, but it won't show layers or let it be saved?  It will finish with the 'middle' and 'inclusive' settings.

 

First I thought it was the model, but I made a new one of some simple holes in Tinkercad and it still won't work.  Is there a wall setting that has to be a particular way to get it to work in exclusive mode?

 

Also, for the past few CURA versions, when I try to save an STL, it gives me an error on the first try with something about access or permissions, but it will save it the second time I try to save it.

 

Was really excited to try the exclusive setting.  The holes not matching design drives me nuts.

 

THX

Edited January 1 by milehigh3dii