The message "Cleaned stack: Message queue exceeded limit, cleaned message queue!" in a log file indicates a protection mechanism kicking in to prevent the memory of the SLLog process from exploding.

This is typically the case when more lines of logging are being queued for writing to logfiles than actual loglines can be written.

The mechanism kicks in when SLLog memory goes over 500 MB, at which time the queue with the largest number of lines is cleared. More info in the 10.2 Release Notes (ID_29989)

The file where the log line appears is the file for which the queue had the largest number or entries in the queue.