Hello
Apologies for having to repost this, given there are a number of older threads concerning this issue, but I cannot seem to find an answer which provides the reason as to why this occurs:
With Microsoft Office 365 ProPlus delivered through Office 2016 Deployment Tool, we are finding that when it comes to updates:
The Microsoft-created scheduled task that runs as SYSTEM fails:
OfficeC2RClient.exe /update SCHEDULEDTASK displaylevel=False
We change this scheduled task, removing silent operation, we see this error returned:
OfficeC2RClient.exe /update SCHEDULEDTASK displaylevel=Full

We change this scheduled task, changing update parameter (task still runs as SYSTEM) and Office will update without issue (both work):
OfficeC2RClient.exe /update USER displaylevel=False
OfficeC2RClient.exe /update USER displaylevel=Full
Test envrionment:
Clean Windows 7 SP1 Professional x64 with IE11 and .NET Framework 4.7.1, fully patched up to 2018-01 Quality Rollup
Single user: Administrator
Standalone machine (not domain-joined)
Office install:
Latest Office 2016 Deployment Tool with following configuration.xml file
<Configuration>
<Add OfficeClientEdition="32" Channel="Broad" Version="16.0.8201.2217">
<Product ID="O365ProPlusRetail">
<Language ID="en-us"/>
<ExcludeApp ID="Groove"/>
<ExcludeApp ID="OneDrive"/>
</Product>
</Add>
<Display Level="None" AcceptEULA="TRUE"/>
</Configuration>
Expected result:
- Office 365 ProPlus x86 1705 Build 16.0.8201.2217 will be installed
- Require end-user to activate application using valid Microsoft Account with Office 365 subscription
- Office applications will keep up-to-date via MS Semi-Annual Channel (will automatically update to 1708 (Build: 16.0.8431.2153) as of 12 Feb 2018 and will check against MS CDN.
Result:
All above true except the automated scheduled task with SCHEDULEDTASK flag does not work. Will only work either with using the update now menu item in Office

Or running OfficeC2RClient.exe /update USER displaylevel=Full
(or displaylevel=False), as described above
Given this information, can anyone explain why the MS Default scheduled task with SCHEDULEDTASK flag, not work?
Thank you in advance for your support
Kind regards
Ivan Hollins