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"Index and length must refer to a location within the string" exception when you try to create a new meeting request or appointment in Exchange Server 2010

Consider the following scenario:
  • You install Microsoft Exchange Server 2010.
  • You create a new meeting request or a new appointment in Outlook Web App (OWA).
  • You click Scheduling Assistant.

In this scenario, the time suggestions may not be displayed as expected. When this issue occurs, you may receive the following error message:
An unexpected error occurred and your request couldn´t be handled.

Additionally, error details that resemble the following are logged:


User host address: ip_address
User: user
EX Address: /o=organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=User1
SMTP Address:
OWA version:
Mailbox server:


Exception type: System.ArgumentOutOfRangeException
Exception message: Index and length must refer to a location within the string. Parameter name: length

Call stack

System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)
Microsoft.Exchange.Clients.Owa.Premium.SchedulingTabRenderingUtilities.SetFreeBusyDayLightBasedValue(ExDateTime startDate, ExDateTime endDate, ExTimeZone timeZone, String& freeBusyData)
Microsoft.Exchange.Clients.Owa.Premium.SchedulingTabRenderingUtilities.RenderRecipientFreeBusyData(TextWriter output, SchedulingRecipientInfo[] schedulingRecipientInfos, FreeBusyQueryResult[] freeBusyQueryResults, ExDateTime startDateFreeBusyWindow, ExDateTime endDateFreeBusyWindow, Boolean show24Hours, Boolean renderDataForAllRecipients, ExTimeZone timeZone, WorkingHours workingHours)

This issue occurs because, under certain conditions, Exchange Server 2010 incorrectly calculates current daylight saving time (DST) start dates and end dates.
To resolve this issue, install the following update rollup:
2685289 Description of Update Rollup 3 for Exchange Server 2010 Service Pack 2
More information
This issue is date dependent. Therefore, it is most likely to occur for mailboxes that use dynamic DST, where the DST start dates and DST end dates change each year.

Article ID: 2719541 - Last Review: 08/21/2012 15:38:00 - Revision: 1.1

Microsoft Exchange Server 2010 Enterprise, Microsoft Exchange Server 2010 Service Pack 1, Microsoft Exchange Server 2010 Service Pack 2

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