Cannot start DBSM (Unknown internal error.)

  • KM02691230
  • 28-Dec-2016
  • 16-Mar-2021


"Cannot start DBSM (Unknown internal error.)" messages are seen on very busy Windows Cell Manager.


On very busy Windows Cell Manager, the following combining errors are seen:

Session Messages:
[Major] From: "DEV"  Time: 17/10/2016 11:49:59
 Cannot start DBSM (Unknown internal error.)
2016-10-17 11:49:59.814  CRS-THREAD.1680.3628 ["/cs/mcrs/w32_mcrs.c $Rev: 51738 $ $Date:: 2016-02-10 06:29:40 ":616] A.09.00 b108
CreateProcess failed in 10 subsequent tries.

App Event Viewer:
Information 17/10/2016 11:49:59 Windows Error Reporting 1001 None "Fault bucket , type 0
Event Name: APPCRASH
Response: Not available
Cab Id: 0

Problem signature:
P1: dbsm.exe


This is caused when the maximum number of child processes that can be spawned by a windows service — desktop heap limits - is reached


The heap size limit needs to be increased as per Installation Guide -  Page 36

The size of each desktop heap allocation is controlled by the following registry value:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\SubSystems\Windows

The default data for this registry value will look something like the following:

%SystemRoot%\system32\csrss.exe ObjectDirectory=\Windows SharedSection=1024,20480,768 Windows=On SubSystemType=Windows ServerDll=basesrv,1 ServerDll=winsrv:UserServerDllInitialization,3 ServerDll=sxssrv,4 ProfileControl=Off MaxRequestThreads=16

The numeric values following "SharedSection=" control how desktop heap is allocated. These SharedSection values are specified in kilobytes.
. 1024 - shared heap size common to all desktops
. 20480 - size of the desktop heap for each desktop that is associated with an interactive window station
. 768 - size of the desktop heap for each desktop that is associated with a non-interactive window station

You must change the SharedSection value that is associated with a non-interactive window station to 20480. A reboot is required for this change to take effect.