Help deciphering logs - system crash same time almost every day

I am looking for help understanding the data provided by the logs at the time of an unexpected reboot. Attached are just a few lines of code right at the time of the reboot.

50	12/09/17 21:30:51.101	luup_log:14: PLEG-14:Daemon:1 <0x755bf520>
06	12/09/17 21:30:55.139	Device_Variable::m_szValue_set device: 110 service: urn:demo-ted-striker:serviceId:PingSensor1 variable: CurrentFailureCount was: 0 now: 0 #hooks: 0 upnp: 0 skip: 0 v:(nil)/NONE duplicate:1 <0x733bf520>
01	12/09/17 21:30:55.139	LuaInterface::CallFunction_Timer device 110 refreshCache took 10 seconds <0x733bf520>
01	12/09/17 21:31:00.006	Failed to get lock(0x1bb1f04) Lua: LuaInterface.cpp:2361 last used LuaInterface.cpp:2361  first used LuaInterface.cpp:1882  thread: 0x77f97320 (>351460)  handler 0x44c740 bOkToFail 0 <0x775bf520>
02	12/09/17 21:31:00.010	Dumping 58 locks <0x775bf520>
02	12/09/17 21:31:00.010	finished check for exceptions <0x775bf520>
02	12/09/17 21:31:00.010	finished check for exceptions <0x775bf520>
02	12/09/17 21:31:00.011	finished check for exceptions <0x775bf520>
.....
01	12/09/17 21:31:00.024	Deadlock problem. going to reload and quit <0x775bf520>
03	12/09/17 21:31:00.025	JobHandler_LuaUPnP::Reload: deadlock Critical 1 m_bCriticalOnly 0 dirty data 1 <0x775bf520>
01	12/09/17 21:31:00.011	Failed to get lock(0x138642c) ThreadedClass: ../ZWave/ZWaveJobHandler.cpp:240 last used ../ZWave/ZWaveJobHandler.cpp:875  first used ../ZWave/ZWaveJobHandler.cpp:875  thread: 0x775bf520 (>351463)  handler 0x44c740 bOkToFail 0 <0x77f97320>
.....
01	12/09/17 21:31:08.226	Main WatchDogRoutine: blocked - terminating 1 <0x6fccd520>

2017-12-09 21:31:08 - LuaUPnP Terminated with Exit Code: 137

The info at the 4th line seems to be the start of the reboot. (12/09/17 21:31:00.006)
Device 14 is one of 4 PLEG instances and device 110 is one of two Ping Sensor instances.
The part I don’t understand is the text portion of line 4. Not sure what object the lock is referring to or if actually was the cause or not. Then finally I get the line with Exit Code: 137. Again, no idea what this means. I have a full 20 minutes of the log files, with 10 minutes pre and post reboot if needed. Any help would be appreciated.

Thanks

I am getting the same thing 4 years later in 7.32, with very similar Logs.