Hi. I have not had stability issues with Platinum for many months.
I agree with it probably being some kind of Windows issue (or with Slate plugins as Noel stated). 
Best of luck

I have the same issues as the OP. Sonar just will not open some projects unless you do it in safe mode. I do not have Slate plug ins at all , I use what comes with Sonar. If you look at the crash dump it is the Bus Compressor module or the Saturation Knob module most of the time causing the problem.

i73930k @4.5 ghz ? I remember a while ago having an overclocked system running well - no crash at all - memtest ok - temp was very low, games were running well ...
 
Then i tried a demo of Mixcraft  and the demo project crashed !!!? Start using Sonar X3 more intensively - Some Crash !!!?
 
One morning i went back to a standard non-overclocked system . Surprise no more crash in Mixcraft and Sonar. Now with Platinum it's super stable (only remember one or two crash since then)
 
my two cents ...

This sounds like a classic case of a computer that is way overdue for a nice fresh start in life. 
Grab a nice new SSD take a deep breath and start fresh. I'll almost guarantee it will work. 
Keep the old drive and use it as a data back up. 
 
 

My old rig from the Sonar 8 days started giving me trouble with X1. It was stable and would sometimes crash, but eventually it just BSOD on any audio exporting I tried to do.
 
I built a new i7 a couple weeks ago and I can say Platinum is more stable than the previous versions, with my new machine I've had zero issues.
 
I hope you get this sorted out, seeing stuff like this to me is like seeing someone broken down on the highway. I know what it feels like and it sucks big time :(

I have problems too.
 
Just not with SONAR Platinum Foxboro.
 
Lately Slate's stuff seems to be OK. The only real problem for me is FG-X will radomly (on a project open) reset all its parms to zero.

bapu
I have problems too.
 
Just not with SONAR Platinum Foxboro.
 

Hihihi

To the OP... your title is disingenuous... You are making an ignorant judgement call, like a climate denier in face of all the evidence to the contrary.  "I'm having serious difficulties getting Platinum to work on my system at the moment... Please HELP" would be an accurate depiction.
 
I really get so fed up/tired of shallow thinking people acting like FOX notnews spreading garbage.  You got issues.  Fine!  But "

Seriously.... Platinum simply is the most unstable software platform ever." 

 
Sound like denier propaganda spread by competing industries.  After reading this thread I don't think that's what you are... I urge you to rejigger your headline... it is pure bullpucky...it's a lie.  Platinum is the most stable platform yet for 99 percent of us... You're obviously here for help...show a little humility and appreciation, along with your frustration.

Check what cakewalk says.Remove slate plugins. No longer crashes?
What's it say in the windows event viewer? Get the full error message.
Lots of people guessing what the problem is here. Get the facts first before you go for more drastic measures.

Standard 'blind' advice normally is...

Backup!

Scan for viruses and malware. After that temporarily disable antivirus.
Run windows update several time Inc optional updates.
Update your plugins.
Update your audio interface and drivers.
Run chkdsk
Goto Intel driver update.
Remove app that might be hogging your resources, process explorer is helpful here.
Consider a motherboard BIOS update.
Run latencymon.

And I do not think that the new title is awesome... Kind of discouraging / annoying, when trying to help. I do not feel the need to get any further into this thread now.