Initialization of external interface failed; Error .

Product: Exchange
Event ID: 9542
Source: MSExchangeIS Public Store
Version: 6.5.6940.0
Component: Microsoft Exchange Information Store
Message: Initialization of external interface <name> failed; Error <error code>.

This event can manifest itself in a few different ways. The description section may specify a different interface and/or a different error code/text. For example:

  • Initialization of external interface NNTP failed; Error ecNotInitialized-MAPI_E_NOT_INITIALIZED.
  • Initialization of external interface WIN32 failed; Error ecServerOOM.
  • Initialization of external interface OLEDB failed; Error Unknown error.
  • Initialization of external interface MAPIRPC failed; Error ecRpcListen.

The underlying cause of the problem will depend on the information in the description line. There will, as well, be other events in the application log, which can provide information. This event is seen in the released version of Exchange Server when the HKEY_CLASSES_ROOT registry hive contains a ProgID subkey with a size that exceeds 259 bytes. This particular issue with the released version of Exchange has now been fixed.

In post-release versions of Exchange Server, this problem can occur if the msExchMaxThreads and msExchMinimumThreads values of the server’s object in Active Directory have incorrect values. The default values are 100 and 10, respectively.
Lastly, this event can occur if the HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Setup key has a “Services” string value that has incorrect data, or has correct data but the permissions on this key are not set correctly.

User Action

Check that the latest service pack has been installed. Check that the msExchMaxThreads and msExchMinimumThreads values are set correctly. Check that HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\Setup has permissions set on it and that it has a “Services” value with correct data.


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