Event 4999 - Watson report about to be sent for process id: 27244 on Mailbox Server every five minutes

On one of my DAG enabled Exchange 2013 mailbox servers, I get this error in event viewer every five minutes:

Log Name:      Application
Source:        MSExchange Common
Date:          6/25/2014 10:49:46 AM
Event ID:      4999
Task Category: General
Level:         Error
Keywords:      Classic
User:          N/A
Computer:    mailboxserver  
Description:
Watson report about to be sent for process id: 27244, with parameters: E12IIS, c-RTL-AMD64, 15.00.0913.022, M.E.RpcClientAccess.Service, unknown, M.E.R.S.U.DatabaseInfo..ctor, System.NullReferenceException, aba8, unknown.
ErrorReportingEnabled: True 

Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="MSExchange Common" />
    <EventID Qualifiers="16388">4999</EventID>
    <Level>2</Level>
    <Task>1</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2014-06-25T17:49:46.000000000Z" />
    <EventRecordID>687360</EventRecordID>
    <Channel>Application</Channel>
    <Computer>mailboxserver</Computer>
    <Security />
  </System>
  <EventData>
    <Data>27244</Data>
    <Data>E12IIS</Data>
    <Data>c-RTL-AMD64</Data>
    <Data>15.00.0913.022</Data>
    <Data>M.E.RpcClientAccess.Service</Data>
    <Data>unknown</Data>
    <Data>M.E.R.S.U.DatabaseInfo..ctor</Data>
    <Data>System.NullReferenceException</Data>
    <Data>aba8</Data>
    <Data>unknown</Data>
    <Data>True</Data>
    <Data>False</Data>
    <Data>Microsoft.Exchange.RpcClientAccess.Service</Data>
    <Data>
    </Data>
  </EventData>
</Event>

Everything is working ok, but I'm concerning that I"m seeing this.  

---

ST