Audio Engine Stops

I have audio engine drop outs too, I do not know why.  I have just always assumed it was related to my audio interface, which is a Focusrite Saffire Pro 14 (maybe the ASIO driver, maybe my latency and buffer sizes.)  These dropouts can occur when adding something, like with your case, or when I stop in the middle of a song, and try to start in the middle of a lot of music happening at once.

I have drop outs as well.  All my pupils are dilated.

When you experience an audio dropout, there's a Toast notification. If none of the above suggestions help, click on the Help button and go through each solution, one at a time, to fix the problem. I have yet to see a dropout problem that the Help menu didn't address.

Thanks Ruckman65. I have never twiddled this value.
 
It never occurred to me to mess with it. Mine doesn't have caching enabled at all. Hmmmm.
 
File System

Enable Read Caching and Enable Write Caching. Choosing either of these options lets SONAR use the Windows disk cache while reading or writing audio data. SONAR will usually perform best with all caching disabled, which is the default setting. If your computer has an older IDE disk controller, or a disk controller that does not use DMA transfers, enabling caching may improve SONAR’s audio performance.

  
Note: Changes to these settings only take effect when you restart SONAR.

I/O Buffer Size. This value determines the buffer characteristics for transfers to and from the disk. Changing this value does not affect audio latency, but will affect the disk throughput for audio tracks. The default setting is 128. A higher value causes more audio to be buffered from the disk ahead of the playback cursor. If you are hearing consistent dropouts/clicks in your audio and if your project contains high bit depth (32/64 bit) or high sample rate audio (88.2K or higher), it may be indicative of a too small I/O buffer size. If so, try a higher I/O buffer size like 256 or 512. If audio problems persist, reset to 128 and try a different remedy.

Also, if you are playing a large file, and using maximum latency, a too-small I/O buffer size may cause dropouts or crashes. Try increasing the buffer size by blocks of 128.

Try turning off caching altogether. The help documentation suggests it's probably better with it turned off, and this is the default setting.
 
Cheers, Peter.