I contacted the Support Community for this error, but I think it is a problem related to the MIP SDK, so I contact this forum again.
The problem did not occur prior to the 2020 R1 version, but it occurs in the latest version.
There are two abnormal things.
First, the Event Server stops with an Unhandled exception.
Second, the Events of the Access Control tab are sometimes not searched in the smart client, and the Event is not delivered in real time, so the alarm does not occur normally.
Here is the unhandled exception message below.
2021-01-31 3:32:10 PM UTC-08:00 Error Unhandled Unhandled exception: System.NullReferenceException: Object reference not set to an instance of an object.
So, I removed the nullable values like below
//AS-IS
// var evt = new ACEvent(Guid.NewGuid().ToString(), Constants.EventTypes.ServerConnected.Id, _client.ServerId, DateTime.UtcNow, Constants.EventTypes.ServerConnected.Name, null, null, null, null);
//FireEventsOccurred(new[] { evt });
//TO-BE
var evt = new ACEvent(Guid.NewGuid().ToString(), Constants.EventTypes.ServerConnected.Id, _client.ServerId, DateTime.UtcNow, Constants.EventTypes.ServerConnected.Name, "", new List<string>(), new List<string>(), new List<ACProperty>());
FireEventsOccurred(new[] { evt });
And I upgraded the MIPSDK from 2017 R2 to 2020 R3. the error is persisted.
The number of the Case is Case: MSC551434 (milestonesys.com)