At first when Windows 10 rolled in, everything was fine. Then came this Hopscotch or whatever upgrade then things started messing up. Latency sucked. Now Ipswitch.....SONAR crashes constantly. I am using a Windows 10, 16 gigs of RAM 8 core. and PLAY from East West. SONAR crashes after a few minutes.
 

Steps to repro please.
Also please exactly do you mean by 'crash'. What actually happens?
Go to Windows update and paste the errors from the event viewer.
Have you tried Sonar safe mode to see of you can rule this down to a plugin?
Have you tried updating your audio interface firmware and drivers and running Windows update?

There are a number of reasons why Sonar could crash so I'm afraid asking everybody if their installs crash will probably lead to red herrings..

Fyi seems to be a number of reports with crashing the play plugins on various DAWs. Update them and make sure you are on 64 bit.

https://www.google.co.uk/...me-mobile&ie=UTF-8

No problems here....I've been pounding on Ipswich all day and not a single crash.  (I'm on Windows 7 Pro 64 bit though)

Faulting application name: SONARPRO.exe, version: 21.8.0.32, time stamp: 0x55fb305a
Faulting module name: ntdll.dll, version: 10.0.10240.16430, time stamp: 0x55c59f92
Exception code: 0xc0000374
Fault offset: 0x00000000000ea28c
Faulting process id: 0x1e70
Faulting application start time: 0x01d0f3f65d41f994
Faulting application path: C:\Program Files\Cakewalk\SONAR Professional\SONARPRO.exe
Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll
Report Id: 5cfd830f-2505-44da-a66a-1137581627f6
Faulting package full name:
Faulting package-relative application ID:

How can I roll back to Gloucester? That version worked perfect
 

ntdll.dll is windows crashing Sonar so check out my first post.

In addition running chkdsk /F and temporarily disabling your virus scanner could resolve it.

Thanks Doktor. I tried all those. I just figured out how to revert back to ?Gloucester? Will see If remains stable.
 

Roll back by while in CCC right click on the Sonar text  and choose your roll back

I rolled back to version "G" and Sonar is no longer crashing when I try to open a big project. It started with version "H" and didn't go away with "I" so I decided to take a step (actually 2 steps) back.
 
Now it works fine.