I hate to be to such a complainer so close to Xmas and all, but... the 2016.12 release is supposed to be just bug fixes, and the bug described in the problem report below (and verified by other users) is still there.  It seems like a real easy fix too.  Some variable is overflowing or something.
 
Anyway, editing midi drum parts is getting frustrating when I try to zoom out and the display jumps all the way out to over 400 bars and can't be zoomed in again unless I use a different slider. Yeah, I know, its not a huge bug and its probably a low priority, but it's starting to drive me nutz. Cheers...   
 
https://www.cakewalk.com/Support/Contact/Problem-Report-Status/54849
 

The link you use in your post gets me to a "My Problem Reports" page and tells me I have no problem reports.

I'll try to paste what I see when I open the link. Hopefully that will work. 

 
CWBRN-54849

Report Details

ProductSONAR PlatinumVersion22.9.2.42Architecturex64StatusNewSummaryThe Magnifying Glass zoom the piano roll view stops functioningRepro Steps

1. Open piano roll view with a drum map
2. Zoom out as far as possible using the magnifying glass style zoom
3. Try to zoom back in again... its not possible.
4. Zoom in using the zoom buttons at the lower right corner of the pianio roll... it still works
5. After zooming in with the lower right hand controls, the magnifying glass zoom works again.

Expected ResultsI expect the hourglass zoom to work and not freeze after zooming out.Actual ResultsActual result is that when zooming with the time line "magnifying glass" method, out the zoom seems to 'jump out' to a few hundred bars fairly easily and then freeze. It is not possible to zoom in again unless it is done with the lower right hand corner zoom controls, After zooming in that way the magnifying glass zoom works again, until it is used to zoom out "too far" then it freezes again.Audio Device OSWindows 7 64-bitReproducibilityReproducibleInAllProjectsFiled10/10/2016Last update10/10/2016

FWIW, I zoom using Ctrl+Alt+Scroll Wheel. It has no problem zooming back in from all the way out.

Thanks for the tip but this does not work for me. (I wish it did, because that would be my workaround).
 
Ctrl+Alt+Scroll Wheel shifts the piano roll display horizontally and Alt+Scroll Wheel shifts it vertically, but neither one actually zooms.  (BTW, I'm using SONAR Platinum x64 2016.12 on Win 7). 
 
When the zoom goes wonky using the magnifying glass method on the bar line, the only recovery for me is the other zoom slider control bar in the lower right-hand corner. Am I missing something?

what about ALT+SHIFT+Z and ALT+Z ?
These are the short cuts for zoom in zoom out / last previous zoom view.
 
EDIT: Never mind, don't think that works in PRV. but I believe it would in Inline PRV.

And YES! I am missing something. 
 
The behavior brundlefly describes with the Ctrl+Alt+Scroll Wheel above is only true for regular midi editing.  The behavior I describe above is only true when editing midi with a drum map in place. Why does zooming methodology behave differently depending upon the presence of a drum map?
 
But, regardless of whether there is a drum map or not, the magnifying zoom on the bar line is still broken. 

The only workaround I can think of (and I tried several that didn't work) is to create a screenset that zooms in enough to "unstick" the notes from the "fully zoomed out & stuck" position.

Sailor55, do you have the midi magnifier engaged in preferences? I'm wondering if that has an interaction with the "live" zooming you are trying to do.

slartabartfast
The link you use in your post gets me to a "My Problem Reports" page and tells me I have no problem reports.

Conclusive evidence there are NO BUGS in SONAR.