Thanks for the logs, it helps diagnose the issue tremendously.
This is due to an intermittent scheduling / unscheduling issue within SmartThings platform that started around Jan 18, 2016.
Line 2984 calls the SmartThings API
Unschedule() function which is apparently broken or randomly working for some (or all?) users. This is within the Talk() function and deals with rescheduling the polling system. Since SmartThings platform is throwing this random exception, the Talk() function never completes when this happens. Code execution stops. I could apply a patch to BigTalker, but either way this scheduling bug breaks the poller which will primarily affect Sonos users ability to detect if a playlist is playing.
I’ll wait a few days and see if SmartThings addresses this bug and try to patch BigTalker with a workaround if they do not.