If you are like me you have a start template set up how you like things to be when you just open up Sonar rather than opening a new project or using a pre-made template.
The new update has probably robbed you of that file and you get a basic "all on one screen" thing come up. If you find your old template (mine was called "Normal") or re-create it, if you save it as a template overwriting the new one called "Basic" you will find you can open Sonar to how you like it just by dismissing the new start screen.
 
If the above means nothing to you then you don't work the same way as I do!
 
Grum. 

Hi. I still have my Normal.cwt unchanged. It was made in september 2013, and has not been altered through any of my updates (including Hopkinton). Sorry for your loss. I keep a copy of mine on an external drive, just in case (still not needed to replace it).
Best of luck.

If you use a non-default project template folder location, nothing gets changed unless you change it.

So it seems my new version of Sonar is unique in changing the default template from "Normal" to "Basic".
Interesting...

Grum.

You can set the default template to be whatever you want it to be.
From File > New ...
 

 
click a template once to select, then click 'Set as Default Template'
 

You can change the default template in the Start Screen by clicking the star in the upper left of the template icon

You can also set the default from the new start screen.  At New From Template, click the really hard to see little start upper left of the template you want to be the default
 

 
 

Pretty cool, huh? 

BobF
You can also set the default from the new start screen.  At New From Template, click the really hard to see little start upper left of the template you want to be the default

old news Bob

scook

BobF
You can also set the default from the new start screen.  At New From Template, click the really hard to see little start upper left of the template you want to be the default

old news Bob

Sorry ... it seemed like ... nevermind