Finding log files for the Presence service
By default, a server log file is created for each BEMS server and is stored daily on the computer that hosts BEMS.
BEMS-Core names the log files gems_<server_name_time stamp>.log.
By default, the BEMS log files are stored daily in C:\BlackBerry\bemslogs.
Note: The timestamp is reset daily at 0:00. It is also reset each time that the Good Technology Common Services service is restarted and when the file size is a maximum of 100 MB.
When the Presence service is restarted, a new log file (LPP-log.txt) is not generated. When the log file reaches 10 MB, a new log is created. When 20 log files are created, the older log files are automatically deleted.
When using BEMS-Presence for Skype for Business on-premises using trusted application mode, the Presence service also writes Lync Presence Provider log files and names files LPP-log.txt. By default, the BEMS Presence log files are stored in C:\Program Files\BlackBerry\BlackBerry Enterprise Mobility Server\Good Presence\Logs\