Event log
The event log records significant events and any errors of communication between the program and the router. Each event line has a brief description of the event and the time when it occurred. If, for example, you enter the wrong login details, this will result in an entry in the event log when you try to start recording. Or if some temporary issue causes a problem in the processing of a sample, this will also result in an event log entry.The event log also records some extra diagnostic information if the option "Save extra diagnostic information" is checked.
Normally the event log should contain only routine events. The occasional error entry in the log probably doesn't have any significance, but if errors are fairly frequent this may indicate a problem, and a copy of the log could help in diagnosing the problem.