Exchange 2013 database dismounts unexpectedly

Errors logged on Exchange 2013:

------------------------------------

Log Name:      Application
Source:        MSExchangeIS
Date:          12/09/2013 8:22:28 AM
Event ID:      1001
Task Category: General
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      
Description:
Microsoft Exchange Server Information Store has encountered an internal logic error. Internal error text is (Unable to apply maintenance insert, index corruption?

-----------------------------

Log Name:      Application
Source:        MSExchangeIS
Date:          12/09/2013 8:22:29 AM
Event ID:      1002
Task Category: General
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      
Description:
Unhandled exception (Microsoft.Exchange.Diagnostics.ExAssertException: ASSERT: Unable to apply maintenance insert, index corruption?

-----------------------------

Log Name:      Application
Source:        MSExchange Common
Date:          12/09/2013 8:22:37 AM
Event ID:      4999
Task Category: General
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      
Description:
Watson report about to be sent for process id: 11204, with parameters: E12, c-RTL-AMD64, 15.00.0712.024, M.E.Store.Worker, M.E.S.Storage.LazyIndexing, M.E.S.S.L.LogicalIndex.HandleIndexCorruptionInternal, M.E.Diagnostics.ExAssertException, 213a, 15.00.0712.000.
ErrorReportingEnabled: True

---------------------------------

KB2846288 appeared to be related but we are already on CU2:

Name                : XXXXXXXX
Edition             : Standard
AdminDisplayVersion : Version 15.0 (Build 712.24)

---------------------------------

Anyone else?

---

Ramu V Ramanan