<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/messages"><soap:Header><t:RequestServerVersion Version="Exchange2013"></t:RequestServerVersion></soap:Header><soap:Body><UpdateItem ConflictResolution="AlwaysOverwrite" SendMeetingInvitationsOrCancellations="SendOnlyToAll"><ItemChanges><t:ItemChange><t:ItemId Id="AAMkAGUxNmQzMzU3LTU1OGYtNDgwYy1hMWQ5LTNiYzhmYzM4MTQ3MABGAAAAAADX7AzcCdnaQJrSv4ml3mgtBwAwEG0Tr1c+S5PCLLuSBAO3AAAAPgS0AAA4fZFkxHWNRr++7Pka0J+kAADf64xMAAA=" ChangeKey="DwAAABYAAAA4fZFkxHWNRr++7Pka0J+kAADf/SpG"></t:ItemId><t:Updates><t:SetItemField><t:FieldURI FieldURI="item:Subject"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:Subject>Testing28</t:Subject></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:Location"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:Location></t:Location></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:Start"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:Start>2014-08-28T11:30:00Z</t:Start></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:End"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:End>2014-08-28T12:00:00Z</t:End></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:LegacyFreeBusyStatus"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:LegacyFreeBusyStatus>OOF</t:LegacyFreeBusyStatus></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="item:ReminderIsSet"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:ReminderIsSet>true</t:ReminderIsSet></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="item:ReminderMinutesBeforeStart"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:ReminderMinutesBeforeStart>15</t:ReminderMinutesBeforeStart></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:IsAllDayEvent"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:IsAllDayEvent>false</t:IsAllDayEvent></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="item:Body"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:Body BodyType="HTML"></t:Body></t:CalendarItem></t:SetItemField><t:SetItemField><t:FieldURI FieldURI="calendar:Recurrence"></t:FieldURI><t:CalendarItem xmlns="http://schemas.microsoft.com/exchange/services/2006/types"><t:Recurrence><t:DailyRecurrence><t:Interval>2</t:Interval></t:DailyRecurrence><t:NoEndRecurrence><t:StartDate>2014-08-28</t:StartDate></t:NoEndRecurrence></t:Recurrence></t:CalendarItem></t:SetItemField><t:DeleteItemField><t:FieldURI FieldURI="calendar:RequiredAttendees"></t:FieldURI></t:DeleteItemField></t:Updates></t:ItemChange></ItemChanges></UpdateItem></soap:Body></soap:Envelope>
<?xml version="1.0" encoding="utf-8"?><s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Header><h:ServerVersionInfo MajorVersion="15" MinorVersion="0" MajorBuildNumber="1015" MinorBuildNumber="18" Version="V2_16" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/></s:Header><s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><m:UpdateItemResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types"><m:ResponseMessages><m:UpdateItemResponseMessage ResponseClass="Error"><m:MessageText>At least one recipient isn't valid.</m:MessageText><m:ResponseCode>ErrorInvalidRecipients</m:ResponseCode><m:DescriptiveLinkKey>0</m:DescriptiveLinkKey><m:Items/></m:UpdateItemResponseMessage></m:ResponseMessages></m:UpdateItemResponse></s:Body></s:Envelope>
While editing recurrence event I am getting the following error
as"At least one recipient isn't valid."
Please help