Not sure how long this has been an issue, since I just installed ASan on this Windows machine.

The update log from Mozilla Maintenance Service:

PATCH DIRECTORY C:\ProgramData\Mozilla\updates\6F193CCC56814779\updates\0
INSTALLATION DIRECTORY C:\Program Files\Firefox Nightly
WORKING DIRECTORY C:\Program Files\Firefox Nightly
Could not disable token privilege value: SeAssignPrimaryTokenPrivilege. (1300)
Could not disable token privilege value: SeAuditPrivilege. (1300)
Disabled unneeded token privilege: SeBackupPrivilege.
Disabled unneeded token privilege: SeCreateGlobalPrivilege.
Disabled unneeded token privilege: SeCreatePagefilePrivilege.
Could not disable token privilege value: SeCreatePermanentPrivilege. (1300)
Disabled unneeded token privilege: SeCreateSymbolicLinkPrivilege.
Could not disable token privilege value: SeCreateTokenPrivilege. (1300)
Disabled unneeded token privilege: SeDebugPrivilege.
Could not disable token privilege value: SeEnableDelegationPrivilege. (1300)
Disabled unneeded token privilege: SeImpersonatePrivilege.
Disabled unneeded token privilege: SeIncreaseBasePriorityPrivilege.
Disabled unneeded token privilege: SeIncreaseQuotaPrivilege.
Disabled unneeded token privilege: SeIncreaseWorkingSetPrivilege.
Disabled unneeded token privilege: SeLoadDriverPrivilege.
Could not disable token privilege value: SeLockMemoryPrivilege. (1300)
Could not disable token privilege value: SeMachineAccountPrivilege. (1300)
Disabled unneeded token privilege: SeManageVolumePrivilege.
Disabled unneeded token privilege: SeProfileSingleProcessPrivilege.
Could not disable token privilege value: SeRelabelPrivilege. (1300)
Disabled unneeded token privilege: SeRemoteShutdownPrivilege.
Disabled unneeded token privilege: SeRestorePrivilege.
Disabled unneeded token privilege: SeSecurityPrivilege.
Disabled unneeded token privilege: SeShutdownPrivilege.
Could not disable token privilege value: SeSyncAgentPrivilege. (1300)
Disabled unneeded token privilege: SeSystemEnvironmentPrivilege.
Disabled unneeded token privilege: SeSystemProfilePrivilege.
Disabled unneeded token privilege: SeSystemtimePrivilege.
Disabled unneeded token privilege: SeTakeOwnershipPrivilege.
Could not disable token privilege value: SeTcbPrivilege. (1300)
Disabled unneeded token privilege: SeTimeZonePrivilege.
Could not disable token privilege value: SeTrustedCredManAccessPrivilege. (1300)
Disabled unneeded token privilege: SeUndockPrivilege.
Could not disable token privilege value: SeUnsolicitedInputPrivilege. (1313)
NS_main: callback app file open attempt 1 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 2 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 3 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 4 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 5 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 6 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 7 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 8 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 9 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file open attempt 10 failed. File: C:\Program Files\Firefox Nightly\firefox.exe. Last error: 32
NS_main: callback app file in use, continuing without exclusive access for executable file: C:\Program Files\Firefox Nightly\firefox.exe
failed: 22
calling QuitProgressUI

1. In about:support click the "Open Folder" button next to the "Update Folder" entry
2. In the directory that is opened navigate to the "updates" subdirectory.
3. Attach the last-update.log and the backup-update.log files if they exist.
4. In the 0 subdirectory attach the update.log and the update.status files if they exist.

Robert, attached all the files I could find of what you requested. update.log in the 0 sub-directory did not exist.

The key is failed: 22, this is MAR_CHANNEL_MISMATCH_ERROR. In bug 1458385 there was a change in how MAR_CHANNEL_ID and ACCEPTED_MAR_CHANNEL_IDS are generated. mar-channel-id was set for ASAN, but accepted-mar-channel-ids was missed, if I'm reading 66f52bda right.

I looked at update-settings.ini in the builds bracketing 66f52bda:

• 2019-07-10-21-50-49 (last build without): ACCEPTED_MAR_CHANNEL_IDS=firefox-mozilla-central-asan
• 2019-07-12-09-59-34 (first build with): ACCEPTED_MAR_CHANNEL_IDS=firefox-mozilla-central

The NS_main: callback app file open attempt %d failed. messages are something else, I suspect this is due to bug 1501311, which I think I can fix. That shouldn't completely block the update like this, though, I think fixing the .yml should fix this.

The product::component has been changed since the backlog priority was decided, so we're resetting it.
For more information, please visit auto_nag documentation.

The above patch seems to be doing the right thing in update-settings.ini in the BoR try builds (vs current mozilla-central).

https://hg.mozilla.org/mozilla-central/rev/afa96907b071