DOCUMENT:Q255890 08-AUG-2001 [winnt] TITLE :PRB: DCOM Client Hangs When You Pass Callback Interface Pointer PRODUCT :Microsoft Windows NT PROD/VER::4.0; winnt:4.0 OPER/SYS: KEYWORDS:kbDCOM kbGrpDSCom kbDSupport ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Advanced Server, version 4.0 - Microsoft Windows NT Server version 4.0 - Microsoft Windows NT Server version 4.0, Terminal Server Edition - Microsoft Windows NT Server, Enterprise Edition version 4.0 - Microsoft Windows NT Workstation version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When a Distributed Component Object Model (DCOM) client makes a remote method call to pass a callback interface pointer to the server, and the SYSTEM account does not have access permissions on the client computer, a problem may occur. If the User Datagram Protocol (UDP) is used, the client may stop responding (hang). If the Transmission Control Protocol/Internet Protocol (TCP/IP) is used, the application may return the E_OUTOFMEMORY error. CAUSE ===== By default, the SYSTEM account does not have access permissions on the client computer; as a result, DCOM cannot marshall the callback interface pointer. RESOLUTION ========== To resolve this problem, give access permissions to the SYSTEM account. For DCOM to work, you must assign access permissions to the SYSTEM account. MORE INFORMATION ================ To check the default access permissions, perform the following steps: 1. Start Dcomcnfg.exe. 2. Click the Default Security tab, and then click Edit Default for default access permissions. The list must include SYSTEM: allow access. If the list is empty, then the launching user and the SYSTEM account have access permissions. REFERENCES ========== For more information on COM security, see the following MSDN Online Library help topic: http://msdn.microsoft.com/library/psdk/com/security_0icz.htm Additional query words: SYSTEM hang ====================================================================== Keywords : kbDCOM kbGrpDSCom kbDSupport Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400 kbWinNTAdvSerSearch kbWinNTAdvServ400 kbNTTermServ400 kbNTTermServSearch Version : :4.0; winnt:4.0 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.