Once, twice, third time lucky (Sonar crash) [Solved: VST reset did the trick]

I have a project with 9 frozen "synth" tracks and one live audio track. If I load Sonar and then click on the project from the initial menu it loads and then immediately shuts the program. Try again and the same thing happens (Sonar does not sit in background so I can restart it straight away). On the third attempt there's every chance that it loads and works fine from there on.
Going back a week or so the crashing was much more severe and Sonar would whitescreen, refuse to die for a while and then hang in the background (I usually then load Reason to clear whatever Sonar is holding on to, close it again and then I can reboot Sonar). Obviously things have improved but it's not a cool way to make music!
Any thoughts?
 
Grum.
  

This is what I get in the Event Viewer:
 
Faulting application name: SONARPLT.exe, version: 21.6.0.25, time stamp: 0x55b7c88a
Faulting module name: SONARPLT.exe, version: 21.6.0.25, time stamp: 0x55b7c88a
Exception code: 0xc0000005
Fault offset: 0x00000000005f8f27
Faulting process ID: 0x1d40
Faulting application start time: 0x01d0cb98d60f315f
Faulting application path: C:\Program Files\Cakewalk\SONAR Platinum\SONARPLT.exe
Faulting module path: C:\Program Files\Cakewalk\SONAR Platinum\SONARPLT.exe
Report ID: 231adc17-378c-11e5-825a-10bf48e30d54
Faulting package full name:
Faulting package-relative application ID:
 
Always run Sonar as Admin.
I've tried loading Sonar using the "shift" method" and it just loads everything one at a time, i.e. there's nothing of interest happening.
I have spent many hours at the Windows update page as I'm one of the lucky ones that keep getting Windows 10 update errors appearing in there!!!
 
Grum.
 

I've spent the afternoon updating to Windows 10 so haven't done much playing with Sonar.
The error message is complete and always looks like that, everything is up to date and nothing explains the third time lucky boot up of Sonar - surely if a plug-in is bad the first time Sonar loads it's still going to be bad the third time?
I don't get it .
 
Grum.
 

Well... Sonar (CW software in general) has some "magic crash X times" features build-in. I just have decided to accept that as a fact. My examples:
 
1) CCC never start for me the first time I try. It asks for admin permissions and then nothing... Second (sometimes third) click works
2) before the latest update RapturePro was crashing during the first attempt to start it and then randomly during each 5-10 restart. Fortunately that effect has disappears with the latest update.
3) After the latest Sonar update I had a crash during project saving. The first pure Sonar crash since long time. The project had just 2 empty audio tracks, no content, no plug-ins. I could not reproduce that.