Exchange 2010 Event ID 4999 Msftefd.exe process crashes

When you work with Microsoft Exchange 2010 SP2 with Rollup 4 or a later update rollup that is earlier than Update Rollup 6 installed, you can meet with Event ID 4999.

If you get following events on mailbox server:

Source: MSExchange Common
Date: Date
Event ID: 4999
Task Category: General
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Description:
Watson report about to be sent for process id: Process ID, with parameters: E12, Build Type, Version Number, ExMSFTE, M.E.Search.ExSearch, M.E.S.Crash.CrashNow, M.E.Common.FailFastException, XXXX, Version Number.
ErrorReportingEnabled: False

Log Name: Application
Source: MSFTESQL-Exchange
Date: Date
Event ID: 64772
Task Category: MSFTESQL Service
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Description:
The filter daemon process MSFTEFD exited unexpectedly.

Log Name: Application
Source: MSFTESQL-Exchange
Date: Date
Event ID: 1053
Task Category: MSFTESQL Service
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Description:
The system exception c000010a was raised at 000007FEF99D0F16.

These events are created, because the incorrect file name extension causes process crash when the Exchange search engine indexes the email message that contains an attached Open Office XML document  with missing a file name extension.

This causes crash of the Microsoft Full-Text Engine Filter Deamon (Msftefd.exe)

Like for now the is workaround like below:

1. Click Start, click Run, type regedit in the Open box, and then click OK.
2. Locate and then select the following registry subkey:
   HKEY_LOCAL_MACHINE\Software\Microsoft\ExchangeServer\v14\ExSearch
3. On the Edit menu, point to New, and then click DWORD (32-bit) Value.
4. Type NeverOverrideAttachmentExtension, and then press Enter.
5. In the Details pane, right-click NeverOverrideAttachmentExtension, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Exit Registry Editor.

This problem should be resolved in Rollup 6 for Exchange 2010 SP2.