Publicfolder access sporadically blocked RCA-Log shows [TooManyObjectsOpenedException] [MapiExceptionSessionLimit] Unable to open message store

Question

Hello,
i am out of ideas with this Problem. Would be nice to get help.
Some users use a shared mailbox (IT-DESK) together to store all information in one mailbox. This users do not have an own mailbox. They login with their AD-Account, start Outlook and configure Outlook to access the IT-DESK mailbox. Credentials are used from
AD-Account with IT-DESK Mailbox. This works fine for all 6 users. But if they are all online, there a problems to access the public Folders. Outlook Shows error message: "Cannot expand the Folder. Your Server Administrator has limited the number of items
you can open simultaneously. Try closing Messages you have opened or removing attachments and Images from unsent Messages you are composing." Close and restart Outlook doesn't help.
If other colleguas Close outloook, this user can acccess the publicfolder.
In Exchange RCA i found errormessage for this user:
2014-12-03T07:28:36.282Z,57821,0,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,172.17.35.4,"Connection Info[GUID:158d46d6-5cba-4b6b-8c08-3fc7cbd8630d, Attempts:1, Flags:0, Ctx:]",fe80::1c0a:e8ab:b626:4768%14,ncacn_http,,b6c2d0fa-1efa-4ac4-9e5a-c189f0fd29ef|d752611f-6b46-411b-ba98-5474f7b29fc0,"""{E6DB4749-720B-4638-A07E-30443009C893}
Outlook=14.0.7108.5000 OS=6.1.7601""",Connect,0,00:00:00,"SID=S-1-5-21-1343024091-448539723-682003330-3285, Flags=None",,,,[email protected]
2014-12-03T07:28:36.313Z,57821,1,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,,,,ncacn_http,Client=MSExchangeRPC,,,PublicLogon,1246 (rop::1246),00:00:00.0160000,"Logon: Public, /o=CompanyName/ou=Exchange
Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=2cf6c46595034516830286b90ef75677-PF_01_MBX_03 in database  last mounted on degrsv0101.CompanyNamedom.goCompanyName.com","RopHandler: Logon: [TooManyObjectsOpenedException] Cannot open mailbox
/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854. -> [MapiExceptionSessionLimit] Unable to open message store. (hr=0x80040112, ec=1246)  [diag::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]  
at M.E.D.S.PublicFolderSession.InternalConnect()     at M.E.D.S.PublicFolderSession..ctor(OrganizationId organizationId, String connectAsUserLegacyDn, Participant connectAsParticipant, IExchangePrincipal publicFolderMailboxPrincipal, Boolean
isPublicFolderHierarchyAccessForUser, WindowsIdentity windowsIdentity, ClientIdentityInfo clientIdentityInfo, OpenMailboxSessionFlags flags, CultureInfo cultureInfo, String clientInfoString, IBudget budget)     at M.E.D.S.PublicFolderSession.Open(String
connectAsUserLegacyDn, MiniRecipient connectAsMiniRecipient, IExchangePrincipal publicFolderMailboxPrincipal, ClientSecurityContext clientSecurityContext, CultureInfo cultureInfo, String clientInfoString)     at M.E.R.H.PublicLogon.OpenPublicFol",,,[email protected]
2014-12-03T07:28:36.313Z,57821,1,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,,,,ncacn_http,Client=MSExchangeRPC,,,,,00:00:00.0160000,"BS=Owner:Sid~CompanyNameDOM\#hol-it~Rca~false,Conn:19,MaxConn:Unlimited,MaxBurst:Unlimited,Balance:$null,Cutoff:Unlimited,RechargeRate:Unlimited,Policy:Symprex,IsServiceAccount:False,LiveTime:02:32:45.8992045",,,,[email protected]
2014-12-03T07:28:36.329Z,57821,2,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,,,,ncacn_http,Client=MSExchangeRPC,,,,0,00:00:00,"Lowest Budget Balance: 2,147484E+09,Session Throttled
Count = 0",,,,[email protected]
2014-12-03T07:28:36.329Z,57821,2,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,,,,ncacn_http,Client=MSExchangeRPC,,,Disconnect,0,00:00:00.0470000,,,ClientRPCCount=0;AvgClientLatency=00:00:00;ServerRPCCount=2;AvgCasRPCProcessingTime=00:00:00.0080000;AvgMbxProcessingTime=00:00:00;MaxCasRPCProcessingTime=00:00:00.0160000;20%ClientPercentile=10;40%ClientPercentile=10;60%ClientPercentile=10;80%ClientPercentile=10;90%ClientPercentile=10;95%ClientPercentile=10;99%ClientPercentile=10;100%ClientPercentile=10;20%CasPercentile=10;40%CasPercentile=10;60%CasPercentile=10;80%CasPercentile=10;90%CasPercentile=10;95%CasPercentile=10;99%CasPercentile=10;100%CasPercentile=20;20%MbxPercentile=10;40%MbxPercentile=10;60%MbxPercentile=10;80%MbxPercentile=10;90%MbxPercentile=10;95%MbxPercentile=10;99%MbxPercentile=10;100%MbxPercentile=10;ClientRpcFailureData:,S:ActivityStandardMetadata.UserId=ADGuid:274ff876-c3ac-441e-9ae3-7d93c24b1276;S:[email protected];S:ActivityStandardMetadata.TenantId=CompanyName.de;S:ActivityStandardMetadata.Component=RCA/Mailbox;S:WLM.BT=Rca;S:ActivityStandardMetadata.Protocol=RPC/HTTP;S:ActivityStandardMetadata.ClientInfo=OUTLOOK.EXE/14.0.7108.5000;I32:ATE.C[DEGRSP0007.CompanyNamedom.goCompanyName.com]=1;F:ATE.AL[DEGRSP0007.CompanyNamedom.goCompanyName.com]=0;I32:ATE.C[degrsv0060.CompanyNamedom.goCompanyName.com]=1;F:ATE.AL[degrsv0060.CompanyNamedom.goCompanyName.com]=0;Dbl:BudgUse.T[]=15.6316995620728;I32:ADS.C[DEGRSP0007]=1;F:ADS.AL[DEGRSP0007]=4.2973;I32:ADS.C[degrsv0060]=1;F:ADS.AL[degrsv0060]=4.829,[email protected]
2014-12-03T07:28:36.329Z,57763,73,/o=CompanyName/ou=Erste administrative Gruppe/cn=Recipients/cn=user94714854,,OUTLOOK.EXE,14.0.7108.5000,Classic,,,,ncacn_http,Client=MSExchangeRPC,,,,0,00:00:00,"BS=Owner:Sid~CompanyNameDOM\#hol-it~Rca~false,Conn:18,MaxConn:Unlimited,MaxBurst:Unlimited,Balance:$null,Cutoff:Unlimited,RechargeRate:Unlimited,Policy:Symprex,IsServiceAccount:False,LiveTime:02:32:45.9148259",,,,[email protected]
ThrottlingPolicy "Symprex" for this user #hol-it has all RCALimits set to unlimited
We have two MS Exchange 2013 SP1 RU6 as DAG running on Windows Server 2012R2.
Three Databases on this Servers:
MailboxDatabase MB_01_2013 on SRV0100
MailboxDatabase MB_02_2013 on SRV0101
PublicFolderDatabase PF_01_2013 on SRV0101 (with publicfoldermailboxes MBX01 structure, MBX02 Folders and MBX03 Folders)
Thanks in advance
Best regards from germany
Wolfram

Answer 1

Hi,
From the error message, it seems that Mapi session exceed the limit.
Please check the registry key MaxObjsPerMapiSession under the following location.
HKEY_LOCAL_MACHINE \SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
The changes become effective when the Microsoft Exchange Information Store service is restarted. Before making any changes in registry, please take the backup of the registry.
Besides, please check the application log to see if there is any related events.
Best regards,
Belinda Ma
TechNet Community Support