Another issue to add to my list of Plt grievances. 
 
I did 2 mix-downs of a song unchecking fast bounce. Following the 2nd successful mix-down, I tried to save the project and Plt crashed to the desktop - no messages of any kind - and as usual, dropped my Quad's drivers for it's system. Restarting Plt gets the usual 'drivers on the system' message, despite still visible and working in Windows.
 
I suppose again I'm the only one experiencing this? 

I don't know what all you've already tried, but your description sounds like the audio drivers disconnecting. Sonar has never been able to gracefully handle unresponsive drivers. I suppose you've done the usual things, re-install the driver, use a usb 2 port not usb 3, check that usb selective disconnect isn't checked in power options. Roland has a firmware update for the quad-capture although I believe it's more for windows 8 compatibility but you might check on that. Hope you get it worked out.

Hi Steve...thanks. I have been in contact with Roland trying to sort out why Sonar keeps these drivers out. Yes to the UIB 2 and no to the selective disconnect usb power setting.
 
I'll have a look at the Win 8 quad driver and sus it out...thanks for that...I'll try anything at this point. 
 
Cheers

The fact that the drivers are stuck after a crash is not a SONAR bug. Most Roland drivers don't handle this scenario by releasing their instance when the calling application terminates. Most other audio interfaces tolerate a crash in the host application and release themselves. The workaround here is to unplug and replug the audio interface.
You should contact Roland support if you need that addressed since there is nothing the DAW can do to resolve it.

The fact that the Roland drivers hang is secondary to the issue of Sonar crashing in the first instance. I'm more interested in finding out why Plt keeps crashing. The workaround is something I've been doing for a year or so.
 
Roland assures me of their 'robust' drivers and has apparently been developed in consultation with Cakewalk. They have not provided a fix for this and ultimately, perhaps I should look to other more reliable audio interfaces.

I know it doesn't help you but, knock on wood, I've really never had any problems with the quad or sonar. I believe at one point in X2 sonar started crashing but just totally removing the quad driver and re-installing fixed the problem. There's also the Kontakt not playing nice with the quad's asio drivers. NI released an update recently but I still can't run Kontakt stand-alone using the asio drivers.
 
If it's driver related, the fact that the drivers stop communicating seems to be what causes sonar to hang/crash. Try going through all the basic troubleshooting steps. Try a different usb cable, try the usb ports on the back of the case or on the front, make sure the quad isn't overheating if you have it stacked with other equipment.
 
Good luck....
 
PS: check for any motherboard bios updates relating to usb power issues.

The driver issue is unlikely to be related to your crash. We can't diagnose your crash without you contacting support and providing us a dump file for the crash. It could be any number of reasons for that including a plugin fault. We won't know until we see the dump file. Its not normal for SONAR to crash when saving so there is something getting corrupted most likely in your project. In any case please provide a crash dump file and we can investigate it further.

I had been using the audio interface in the V-Studio and experienced lots of crashing problems that as Noel points out, were not SONAR-related. The Octa-Capture did the same thing, but when I downloaded its most recent drivers and firmware, it worked much better. I assume the V-Studio audio interface will not be updated further although, I'm going to re-install its drivers and give it one more try soon.
 
Meanwhile, I tested the TASCAM US-4x4 interface when it first came out and really liked the preamps. So I started using that, and it's been super-reliable but then again, I knew it had been tested extensively with SONAR. I'm not saying by any means it's the only interface to use, I've tested a ton of interfaces over the years and some just seem to be more Windows-friendly than others.
 
I may just be lucky but Platinum has been unusually reliable for me. Still haven't had a crash or hang since installing the final version. I'm sure I'll figure out some way to break it, but haven't yet.

Noel Borthwick [Cakewalk]
The driver issue is unlikely to be related to your crash. We can't diagnose your crash without you contacting support and providing us a dump file for the crash. It could be any number of reasons for that including a plugin fault. We won't know until we see the dump file. Its not normal for SONAR to crash when saving so there is something getting corrupted most likely in your project. In any case please provide a crash dump file and we can investigate it further.

I have submitted a tech support request over a week ago...I have sent numerable dump files when Sonar crashes...sometimes there's a connection error.
 

Anderton
I had been using the audio interface in the V-Studio and experienced lots of crashing problems that as Noel points out, were not SONAR-related. The Octa-Capture did the same thing, but when I downloaded its most recent drivers and firmware, it worked much better. I assume the V-Studio audio interface will not be updated further although, I'm going to re-install its drivers and give it one more try soon.
 
Meanwhile, I tested the TASCAM US-4x4 interface when it first came out and really liked the preamps. So I started using that, and it's been super-reliable but then again, I knew it had been tested extensively with SONAR. I'm not saying by any means it's the only interface to use, I've tested a ton of interfaces over the years and some just seem to be more Windows-friendly than others.
 
I may just be lucky but Platinum has been unusually reliable for me. Still haven't had a crash or hang since installing the final version. I'm sure I'll figure out some way to break it, but haven't yet.

Thanks Anderton...I'm tired of unplugging and plugging in the Roland...I re installed the drivers a couple of times now. I'll have a look at the Tascam...I've just about had enough of this.
 
PS. Doesn't look like it has digital input/outputs?