Event ID 1002 when the store worker process crashes in Exchange Server 2019 and 2016

In Microsoft Exchange Server 2019 or Exchange Server 2016, assume that you have several database availability groups (DAGs) that have multiple mailbox databases. You could experience an issue that the store worker process crashes randomly for different mailboxes on different databases. Additionally, the following event is recorded in the application event log:

Time:     Time

ID:       1002

Level:    Error

Source: MSExchangeIS

Machine:  ComputerName

Message:  Unhandled exception (System.NullReferenceException: Object reference not set to an instance of an object.

   at Microsoft.Exchange.Server.Storage.StoreCommonServices.AddressBookEID.IsAddressBookEntryId(Context context, Byte[] entryId, Eidt& eidt, String& emailAddr)

   at Microsoft.Exchange.Server.Storage.StoreCommonServices.AddressInfoGetter.GetAddressType(Context context, ISimpleReadOnlyPropertyBag bag, AddressInfoType ait)

…

For Exchange Server 2019, install the Cumulative Update 1 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.

Learn about the terminology that Microsoft uses to describe software updates.