Facts: Using Sonar forever. On Platinum, latest release.  Win 10, Big Ass Huge Computer (32GB Ram, EVGA Classified MB, 12 Cores 5820K, SSD Samsung 840, Audient ID22, every bit of information about my system is pasted below).
 
PROBLEM: The Pesky Audio Engine Stopped Unexpectedly.
It's not a driver latency issue, no matter the latency, Sonar decides to STOP playing audio at very specific points of my projects. The current project is no exception as the beast just arrived. Yay! Read on.. if you dare...
 
Let's start with, in this case, two Sonar files to keep the dark illustration simple:
1) Main Project File - 32 Bit, 44K. All working well... then...
2) Drum Tracking File - 32 Bit, 44K. Select One Bar and 8 tracks of drums, Bouncing the clips so it doesn't copy the whole 180MB audio file then paste to #1 Main Project File.
3) Play audio and BAM!!! Yes, The Audio Dropout shows up and the file won't play at this specific pointer. It won't even start running within this one bar section. I have to go a few bars earlier for it to start playing always to FAIL at the specific pasted section.
 
What I've tried to do:
Does not work: Increase latency on the Audience ID22 (Awesome audio interface, way better then my previous RME Babyface BTW).
Does not work: Turn off ALL plugins with the FX button so CPU is at near zero.
Does not work: A brand new, practically empty 1TB SSD hard drive.
 
Happens in many Sonar projects: Once I get going on a project, it can expand to many tracks, but eventually, some recorded audio will screw me. The dropout is NEVER with a synth. 
 
Impractical Solution: With my Sonar projects, it's always some audio that I recorded that eventually is the problem. I run around the file freezing tracks, that previously worked, like guitar, vocals, etc.. and then, finally the dropout goes away.  
 
Check out this hilarious fix to the problem above in #1 Main File.  a) Take the 8 new tracks, one bar and FREEZE them. Yay, it works and audio won't drop out. Wait, kids, it gets better.  UNDO the bounce and it STILL works without an audio dropout.  Huh?  So apparently, Sonar interprets, caches, indexes, waveform previews, or "who knows?" the original audio file a certain way, but it's corrupt to give a dropout. Is the "Audio Dropout" error (Ummm bug) just lazy programming and the real error isn't showing up? I do get the major pop-up error about corrupt audio in the advanced stages of this dilemma at times, BTW.
 
Is this my solution? Bounce and unbounce every new audio recorded track? (I'll try it for now). Is the bug in the waveform preview?   These files are simple audio files so certainly aren't causing a CPU issue. Whatever plugins are on the tracks does not make a difference. Freezing audio in Whack-a-mole fashion is not a workable solution as it adds way too much time to the production process. "In the midst of creative bliss, the dark clouds descended and the buzzkill grim reaper arrived to slaughter the ecstatic treble vibes of the unsuspecting producer."
 
It is possible: That this bug only appears when PASTED audio exists in a track. So the PASTE function may be the culprit, which is clear in the example above.
 
YOUR SOLUTION: 
How can I use Sonar professionally? It's the end of the road. Lucky me, I own "Lifetime Updates" (at present) from Hell!!!  Get your bank account ready to receive CASH because you're a genius who has the iron-clad fix to this problem. $$ Reward to fix this problem, which is very likely a BUG in Sonar.  You can even come to my house in Los Angeles. I will pay you $$$.
 
Thank you,
 
DannyK
 
SIV64X - System Information Viewer V5.12 MINTYJAMBOX::minty
Windows 10 x64 Professional (Single User) V10.00 Build 10586 TH2 EVGA 151-HE-E999 MINTYJAMBOX::minty English (0409) United States (1)
Workgroup WORKGROUP 00 12:45:52 2016-09-12 13:51:08 [2.13GHz Quad DDR4 RAM] PCIe x8@1 (x8@3) CLK:DRAM 3:32 PKG 48°C
Resource Usage 46% [1] 12% Current Maximum DDR4 RAM CAS Latency 15
System Physical Memory 15.00GB 933.66MB 32.00GB RAS to CAS Delay (tRCD)15
System Paging File 16.90GB 19.77GB 36.68GB RAS Precharge (tRP) 15
System File Cache 16.27GB 12.81GB 29.07GB Cycle Time (tRAS) 35 (4)
Row Cycle Time (tRC) 50 2T
CPUs 12 Cores 6 Chips 1 Disks 31°C 32°C 36°C 29°C NA 37°C NA DIMMs 38°C 36°C 37°C 37°C
Sensor Fintek F71889A MB 40°C 34°C I/O +3.33 PSU +5.47 +7.68 +5.04 VBAT +3.36 Fans 1,236 0 0 0
Processor Clock 0.8% CPU Utilisation Volts Temp Power APIC Socket R2 LGA-2011-3 Intel Core i7 Hexa 5820K (Haswell-E) 3.30GHz [R2]
CPU-0 1.20GHz x12 100MHz K 1% 0.75 36°C 39.51 0.0.0 Technology 22nm x64 Family 6 Model 63 (3F) Stepping 2 Revision 36
CPU-1 1.20GHz x12 100MHz CPU-1 is Idle 0.0.1 CPUs 12 Cores 6x2 Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz
CPU-2 1.20GHz x12 100MHz U 2% 0.75 36°C 39.51 0.1.0 L1 Code Cache (2) 8-way 64-byte 6 x 32KB Core 0.78 volts
CPU-3 1.20GHz x12 100MHz CPU-3 is Idle 0.1.1 L1 Data Cache (2) 8-way 64-byte 6 x 32KB [3/3]Temp 42.0°C (41-43)
CPU-4 1.20GHz x12 100MHz CPU-4 is Idle 0.75 35°C 39.51 0.2.0 L2 Unified Cache (2) 8-way 64-byte 6 x 256KB [8]Fan 1,236 RPM
CPU-5 1.20GHz x12 100MHz D 2% I 1% 0.2.1 L3 Unified Cache (12) 20-way 64-byte 1 x 15MB [25]Power 37.05 Watts
CPU-6 1.20GHz x12 100MHz CPU-6 is Idle 0.75 33°C 39.51 0.3.0 [Cache-0 Latency] [MMX SSE4.2 XD VMX AVX2] Agent 1.20GHz
CPU-7 1.20GHz x12 100MHz CPU-7 is Idle 0.3.1
CPU-8 1.20GHz x12 100MHz U 1% 0.75 37°C 39.51 0.4.0 Memory GPU 2.0% GPU Utilisation Volts Temp Video
CPU-9 1.20GHz x12 100MHz I 1% 0.4.1 GPU-0 405MHz P8 135MHz Activity 4.0 % 0.99 37°C 405MHz
CPU-10 1.20GHz x12 100MHz K 2% 0.77 37°C 39.51 0.5.0 GPU-1 405MHz P8 135MHz Activity 0.0 % 0.99 37°C 405MHz
CPU-11 1.20GHz x12 100MHz U 2% 0.5.1
[ OK ] [ Copy] [Windows] [Machine] [Status] [USB Bus] [Network] [ SPD ] [Volumes] [Adapters] [PCI Bus] [ About] [ Help]

If the audio can't stream, the engine will stop. This is what led me to find the Week 35 tip in the "Friday's Tip of the Week" thread. Don't know what graphics card you're using, but check if there are other audio drivers installed as part of your graphics driver package that have the capability to take over your system. Some high-performance cards prioritize graphics over audio.
 
There's zero guarantee this is the issue, but it's easy to check so there's no harm in seeing if it makes a difference. Other than that, some quality time with DPC latency checker might reveal what's pushing SONAR aside. That it happens in the same place every time doesn't necessarily implicate SONAR if there's a lot of feverish pointing to various places on your data drive happening more or less simultaneously.
 
Good luck. Maybe someone else has experienced this and can help, but I cannot begin to tell you how much disabling "rogue" drivers made my entire system so much happier for real-time streaming. BTW - even if you do disable drivers, sometimes Windows will be "helpful" and re-enable them when updating.
 
It seems unlikely it's a bug in SONAR because if it was, this forum would be lit up with people having similar problems.

If I bring you my computer and we load your project and it DOES NOT happen, what is my $reward?
 

  It would be great to have you pay for a round trip from MSY to LAX. However, I think if you would select your imported clips and then do a "bounce to clips" instead of freezing they will then work correctly.

I live in Thousand Oaks. Downtown L.A. is only a 30 minute drive (not in rush hour though).

What I would try is, after you create a bounce or copy paste or other things that seem to make it drop out. After you preform the action and before you hit play, save project and exit, reboot… Then hit play…
 
peace!

Once I was beta testing some high performance VST and I was getting dropouts.
I changed the Config file settings 'DropoutMsec' to 500.
I think that helped, but I also increased 'ExtraPluginBufs' and maybe some other stuff.
That was a year or two ago and I haven't changed them back, so I think they are harmless changes.
 
Might not help you at all.
 
LatencyMon from Resplendence.com is valuable.
 

Without painstakingly re-reading to separate the factual wheat from the editorial chaff of your description of the symptoms and conditions, I'm going to jump out on a limb and guess that this is probably an audio file streaming issue, and you need to increase your disk playback buffer or move the project audio to a faster drive. You didn't mention anything related to disk usage or performance which would be particularly relevant to an issue that crops up once the track count gets to a certain point.
 
Copying the project with all its audio to a new per-project folder might help consolidate the audio files to reduce seek/read times that are causing a dropout.
 
Anti-virus software could also be a factor.

Just a random thought, but could it be related to 32-bit audio? I'm pretty sure most people(?) use 24-bit because there's plenty of headroom there.   Does bouncing to 24-bit files make a difference?

What type of files are you pasting? Could they be from iTunes, by any chance?