ODMAD: ReACL Error “Unable to update Registry key WcmSvc\Tethering\Roaming: RegGetKeySecurity: The data area passed to a system call is too small” (4380760)

During device cutover, the ReACL phase may fail on certain machines with a registry-related error referencing "Software\Microsoft\WcmSvc\Tethering\Roaming".  You will find the following errors in Device Agent logs (agent_xxx.log). It can appear during BT-ReACLPrepareWin10Profiles or sometimes BT-ReACL step:

Error[##]: CmdLine job BT-ReACLPrepareWin10Profiles is failed. Unable to update Registry key '…\Software\Microsoft\WcmSvc\Tethering\Roaming': System.ComponentModel.Win32Exception (0x80004005): RegGetKeySecurity: The data area passed to a system call is too small

Although the cutover may still continue, the error can interrupt profile preparation and may cause partial profile migration or require a second cutover attempt.

The registry key SOFTWARE\Microsoft\WcmSvc\Tethering\Roaming belongs to the Windows Connection Manager Service (WcmSvc) and stores tethering/roaming network settings.

This key often has a large or complex security descriptor (ACL). When the ODMAD Device Agent attempts to read or re-ACL this key, the Windows API call RegGetKeySecurity may fail with the error: “The data area passed to a system call is too small.”

The failure occurs because the buffer used to retrieve the ACL is insufficient for the descriptor’s size/complexity.

• Adding the affected registry path to the ReACL Profile exclusion list should resolve the issue.
  • On the “Exclude these registry keys from processing” field, add the following entry on a new line: 

**\Software\Microsoft\WcmSvc\Tethering\Roaming