invocation. : The EventBusInterop Container property is null.
at SourceCode.EventBus.Server.EventQueueProcessing.ExecuteAssembly(Int32 CustomEventInstanceID, Int32 CustomEventID, ResolvedPolicyMapping resolvedPolicyMapping, Boolean isConditional, Int32 eventTypeID)
at SourceCode.EventBus.Server.EventQueueProcessing.ProcessEvent(Int32 ID)
Using the following SQL command we determined that there were multiple Server Names with the same HostName but different ports:
SELECT * FROM [K2].[HostServer].[Server]
We treat the HostName as unique, there is some logic that gets over overridden on K2 Server startup, that then fails to initialize the EventBusInterop Assemblies that Notification Emails rely on.
We removed the Servers from the [K2].[HostServer].[Server] table that was no longer in use, using the following script:
[HostPort] = OLD_PORT_NUMBER
Email notifications were send after a K2HostServer restart.