You may encounter entries similar to the following in stderr log:
2015-03-31 17:28:24.730 [STDERR] Child process with pid: 21506 was killed by signal: 15, core dump: 0 2015-03-31 20:24:58.729 [STDERR] Child process with pid: 8619 was killed by signal: 15, core dump: 0 2015-03-31 20:40:04.730 [STDERR] Child process with pid: 9648 was killed by signal: 15, core dump: 0 2015-04-01 02:00:35.731 [STDERR] Child process with pid: 9976 was killed by signal: 15, core dump: 0
These types of entries are actually quite normal. They normally happen during LSWS's graceful restart and are actually information which can be safely ignored, not errors.