ExchangeFreeBusyService error, "System.NullReferenceException: Object reference not set to an instance of an object." (4347933)

When a Notes user creates a meeting and tries to query free busy data for an Exchange (or Office 365) user, the query may fail with the following error:

2016-01-04 13:49:34,171 [19] INFO  AutodiscoverResultCache - user@domain.com found in cache. Returning https://outlook.office365.com/EWS/Exchange.asmx
2016-01-04 13:49:34,171 [19] INFO  EwsWorker - Sending EWS request to Exchange
2016-01-04 13:49:37,608 [19] INFO  EwsWorker - Receiving EWS response from Exchange 00:00:03.4425098
2016-01-04 13:49:37,624 [19] ERROR ExchangeFreeBusyConnector - GetFreeBusyInfo()
System.NullReferenceException: Object reference not set to an instance of an object.
   at Dell.CMX.API.Core.FreeBusyExchange.EwsWorker.CreateUserFreeBusyList(TimeWindow timeWindow, IList`1 emailAddressList, GetUserAvailabilityResults availabilityResults)
   at Dell.CMX.API.Core.FreeBusyExchange.EwsWorker.GetUserAvailability(Uri ewsUri, SmtpEmailList smtpEmailList, DateTime startTime, DateTime endTime)
   at Dell.CMX.API.Core.FreeBusyExchange.ExchangeFreeBusyConnector.GetFreeBusyInfo(SmtpEmailList smtpEmailList, DateTime requestStartDateTime, DateTime requestEndDateTime)

WORKAROUND 1:

Set the "working hours" for all users experiencing this error with the following PowerShell command as an example:

Set-MailboxCalendarConfiguration -Identity user@domain.com -WorkingHoursTimeZone "Pacific Standard Time" -WorkingHoursStartTime 08:00:00 -WorkingHoursEndTime 17:00:00

If all users in the environment share the same "working hours", then you may be able to use a command such as this example to set the "working hours" for all users in the environment at the same time:

Get-Mailbox -ResultSize unlimited -RecipientTypeDetails UserMailbox | Set-MailboxCalendarConfiguration -Identity user@domain.com -WorkingHoursTimeZone "Pacific Standard Time" -WorkingHoursStartTime 08:00:00 -WorkingHoursEndTime 17:00:00

WORKAROUND 2:

Coexistence Manager for Notes (CMN) 3.7 added a new feature:

• Option to show Exchange users' non-working time in free/busy lookups from Notes: CMN now offers the option of Notes free/busy queries showing Exchange users' non-working time, in addition to the booked calendar events. (Notes users' non-working time already appeared in Exchange users' lookups.) The option is controlled by a new checkbox at the bottom of the Exchange Free/Busy screen.

This new feature can be turned off by unchecking the checkbox in the following screenshot and then Saving and Activating the Free Busy Connector:

STATUS

This issue has been resolved in CMN 3.7.0.26. Please contact Quest Support for the latest version of CMN.