Hello, I have an Single multiple child domain controller scenario. Everything was working fine till day before, clients started reporting that they ain't recieving updated OAB in outlook. After some research in Exchange server OAB folder we found that folders OAB folder exists with its sub folders (a long GUID) but we were not able to see the same folders under IIS-->OAB virtual directory. Wwe have then manualy tried updating the OAB which gave an error below....                                                                                                                                                                                                                                                       " Generation of OAB "\Global_OAB" failed. Dn: CN=Global_OAB,CN=Offline Address Lists,CN=Address Lists Container,CN=Vedanta Exchange Org,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=vedantaresource,DC=local      
ObjectGuid: 932afc69-0712-4992-a9bd-57df6c0e02f5      
Stats: S:OAB='\Global_OAB';I64:Status=2147500037;Dt:StartTime=2015-04-01T06:15:23.8692958Z;Dt:EndTime=0001-01-01T00:00:00.0000000;S:DC=;I32:Total.Records=0;I32:Total.TempFiles=0;Ti:TimeWritingFiles=00:00:00;S:Org=vedantaresource.local;S:Wasted=False;I32:Total.RecordsAddedChurn=0;I32:Total.RecordsDeletedChurn=0;I32:Total.RecordsModifiedChurn=0;I32:MailboxDownload.FS.BytesRead=6211212;I32:MailboxDownload.FS.BytesWritten=6211212;Ti:MailboxDownload.FS.Reading.ElapsedTime=00:00:00.3238458;Ti:MailboxDownload.FS.Writing.ElapsedTime=00:00:00.1273409;Ti:PrepareFilesForOABGeneration.DownloadFilesFromMailbox.StoreRpcLatency=00:00:01.7970000;I32:PrepareFilesForOABGeneration.DownloadFilesFromMailbox.StoreRpcCount=1067;Ti:PrepareFilesForOABGeneration.DownloadFilesFromMailbox.CpuTime=00:00:03.1718750;Ti:PrepareFilesForOABGeneration.DownloadFilesFromMailbox.ElapsedTime=00:00:05.4275814;Ti:PrepareFilesForOABGeneration.CpuTime=00:00:03.1718750;Ti:PrepareFilesForOABGeneration.ElapsedTime=00:00:05.4277854;Ti:Total.CpuTime=00:00:03.1718750;Ti:Total.ElapsedTime=00:00:05.4278649;;      
S:Exp=System.UnauthorizedAccessException: Access to the path is denied.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.File.InternalMove(String sourceFileName, String destFileName, Boolean checkHost)
   at Microsoft.Exchange.MailboxAssistants.Assistants.OABGenerator.OABGenerator.SafeFileReplace(String sourceFile, String destinationFile)
   at Microsoft.Exchange.MailboxAssistants.Assistants.OABGenerator.OABGenerator.DownloadFilesFromMailbox(MailboxSession mailboxSession)
   at Microsoft.Exchange.MailboxAssistants.Assistants.OABGenerator.OABGenerator.PrepareFilesForOABGeneration(AssistantTaskContext assistantTaskContext)
   at Microsoft.Exchange.MailboxAssistants.Assistants.OABGenerator.OABGeneratorAssistant.<>c__DisplayClassc.<ProcessAssistantStep>b__8()
   at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(TryDelegate tryDelegate, FilterDelegate filterDelegate, CatchDelegate catchDelegate)
   at Microsoft.Exchange.MailboxAssistants.Assistants.OABGenerator.OABGeneratorAssistant.ProcessAssistantStep(AssistantTaskContext assistantTaskContext) "                                                                                                                                                                                                                                                                                                                                                                           We do not understand why the problem has caused all of a sudden. Requesting help in this regards.                                                           &n

Hello

check oab directory ntfs security, need system and administers full control inherited all subfolder and files, and auth user read.
or start procmon and monitor access denied.

Thanks Sneff_Gabor for your response. Let me try and confirm what you've suggested. will post the output soon

Hi,

Basic on the error message System.UnauthorizedAccessException: Access to the path is denied., I recommend that move OAB generation server to other Mailbox server for testing.
Move-OfflineAddressBook -Identity "My OAB" -Server SERVER01

As additional to Gabor, please pay attention to below link about A security group does not have sufficient rights to an OAB folder:
https://technet.microsoft.com/en-us/library/dd535384(v=exchg.80).aspx

Thanks

Tried that Sneff_Gabor .. didn't helped.

Hello

procmon not show access denied? like:

Hi,

Any update about this pr

Sorry for the delayed response since we have stuck with some other issues.

The problem is still there :(  however we are working on it and will post the findings soon.

Hi,

How about move OAB generation server to other Mailbox server as I mentioned above?
Please run below command to force update address list:
Get-AddressList | update-AddressList
Get-GlobalAddressList | update-GlobalAdressList
Get-OfflineAddressBook | Update-OfflineAddressBook

Thanks