Microsoft-Windows-Eventlog : Audit events have been dropped by the transport. 0

Microsoft-Windows-Eventlog : Audit events have been dropped by the transport. 0

What dis this mean and should I be concerned about this. We have just installed the distributed version and I am new to eventlog analyzer. 

I ma alos looking for some good online vidoes that shows me how to use this and what is required to configure the tool for compliance as well as reports and alerts