Hi everybody,

I have a problem, the solution of which is to increase MailboxLockMaximumWaitCount from 10 to 50. But where to have this in configuration?

The log which tells the problem is:

"ExceptionHandler_Execute=Microsoft.Exchange.Data.Storage.StorageTransientException: Cannot open mailbox /o exchange/ou exchange administrative group (fydibohf23spdlt)/cn recipients/cn 36b3a4113b5f46478724738a0488c3f6-tecex303. ---> Microsoft.Mapi.MapiExceptionTimeout: MapiExceptionTimeout: Unable to open message store. (hr 0x80040401  ec -2147220479)
Diagnostic context:
    Lid: 55847   EMSMDBPOOL.EcPoolSessionDoRpc called [length 511]
    Lid: 43559   EMSMDBPOOL.EcPoolSessionDoRpc returned [ec 0x0][length 248][latency 0]
    Lid: 52176   ClientVersion: 15.0.995.32
    Lid: 50032   ServerVersion: 15.0.995.6032
    Lid: 23226   --- ROP Parse Start ---
    Lid: 27962   ROP: ropLogon [254]
    Lid: 17082   ROP Error: 0x80040401
    Lid: 26937  
    Lid: 21921   StoreEc: 0x80040401
    Lid: 27962   ROP: ropExtendedError [250]
    Lid: 1494    ---- Remote Context Beg ----
    Lid: 53152   dwParam: 0xA
    Lid: 35440   StoreEc: 0x80040401
    Lid: 57721   StoreEc: 0x80040401
    Lid: 61692   StoreEc: 0x80040401
    Lid: 54056   StoreEc: 0x80040401
    Lid: 56872   dwParam: 0xFE
    Lid: 42712   StoreEc: 0x80040401
    Lid: 10786   dwParam: 0x0        Msg: 15.00.0995.032:CHRP5100
    Lid: 1750    ---- Remote Context End ----
    Lid: 26849  
    Lid: 21817   ROP Failure: 0x80040401
    Lid: 26297  
    Lid: 16585   StoreEc: 0x80040401
    Lid: 32441  
    Lid: 1706    StoreEc: 0x80040401
    Lid: 24761  
    Lid: 20665   StoreEc: 0x80040401
    Lid: 25785  
    Lid: 29881   StoreEc: 0x80040401    at Microsoft.Mapi.MapiExceptionHelper.InternalThrowIfErrorOrWarning(String message  Int32 hresult  Boolean allowWarnings  Int32 ec  DiagnosticContext diagCtx  Exception innerException)    at Microsoft.Mapi.ExRpcConnection.OpenMsgStore(OpenStoreFlag storeFlags  String mailboxDn  Guid mailboxGuid  Guid mdbGuid  String& correctServerDn  ClientIdentityInfo clientIdentityAs  String userDnAs  Boolean unifiedLogon  String applicationId  Byte[] tenantHint  CultureInfo cultureInfo)    at Microsoft.Mapi.MapiStore.OpenMapiStore(String serverDn  String userDn  String mailboxDn  Guid guidMailbox  Guid guidMdb  String userName  String domainName  String password  String httpProxyServerName  ConnectFlag connectFlags  OpenStoreFlag storeFlags  CultureInfo cultureInfo  Boolean wantRedirect  String& correctServerDN  ClientIdentityInfo clientIdentity  Boolean unifiedLogon  String applicationId  Client xropClient  Boolean wantWebServices  Byte[] clientSessionInfo  TimeSpan connectionTimeout  TimeSpan callTimeout  Byte[] tenantHint)    at Microsoft.Mapi.MapiStore.OpenMailbox(String serverDn  String userDn  Guid guidMailbox  Guid guidMdb  String userName  String domainName  String password  ConnectFlag connectFlags  OpenStoreFlag storeFlags  CultureInfo cultureInfo  ClientIdentityInfo clientIdentity  String applicationId  Byte[] tenantPartitionHint  Boolean unifiedLogon)    at Microsoft.Exchange.Data.Storage.MailboxSession.ForceOpen(MapiStore linkedStore  Boolean unifiedSession)    --- End of inner exception stack trace ---    at"

Kindly help.

Thanks & regards,

Amit Jha

• Edited by jha.amit6666 Tuesday, May 19, 2015 6:44 AM

Hi Lynn-Li,

I tried to reproduce the problem. Kindly confirm the info: The logs are in %ExchangeInstallPath%/Logging/Ews. And, changing "MailboxLockMaximumWaitCount" in the location told by you is giving different problem. Here is the snapshot which may be helpful. 

More information is here, but I am not getting how to again replicate this: Mailbox lock contention in Exchange 2013 - Bill Long's Exchange Blog - Site Home - TechNet Blogs

• Edited by jha.amit6666 16 hours 17 minutes ago