COM client failing with error 8000401a
The error 8000401a (CO_E_RUNAS_LOGON_FAILURE) means "The server process could not be started because the configured identity is incorrect. Check the username and password".
Many a times we have seen that the error occurs from a DCOM server that is configured to launch as “The Interactive User” user account especially on Windows Vista and above OS's. This worked fine on Windows 2003 but on Windows Vista and above OS's you notice certain scenarios where the application fails to launch. For example,
a. If you log off the machine and don’t have a remote desktop session connected to the server OR
b. You disconnected a RDP session (that was used to connect to the DCOM server machine) without logging off.
This is by design due to new session management features of Windows Vista and above OS's.
Both (a) & (b) are similar with respect to interactive user logon. Reason: Disconnecting a RDP session means "no currently interactive user logged on". This makes sense because an "interactive logon" would mean that someone actually has the ability to respond to some GUI based features should the DCOM server use any GUI items. If you’ve closed down a RDP session and/or don’t have anyone logged onto the machine then if the DCOM server does require GUI response, it will hang because there is no interactive session to respond to it.
The best possible ways to resolve this is by:
(I) Change the identity of the DCOM server from “The Interactive User” to “This User” and then specify that the DCOM server runs as admin or some other domain or local user account.
(II) Make sure that someone is physically logged onto the machine or that you continuously have a remote desktop session open.
Applies to:
- Windows 7
- Windows Server 2008 R2
- Windows Server 2008
- Windows Vista
- Windows 8.0/ 8.1
Additional References: