SharePoint Pain

[Tested on SharePoint 2016 only] Applying the September 2025 SharePoint Cumulative Updates to SharePoint On-Prem was a bit chaotic as it introduced a number of bugs. It would have been better if I had the option to skip it and go straight to the October CU. Stefan, the Sr. SharePoint Escalation Engineer at Microsoft, has summarized the issues very well on  his blog . While many of the issues have been fixed in the October CU release, the fix for the "installation of this package failed" error  was not included for those who had already applied the September CU before the fix was made. That is, the System and Local Service accounts have to be manually removed from the WSS_WPG and IIS_IUSRS groups before applying the October CU. Without this step, I encountered a new popup error that said: Error 2349. An internal error has occurred. ( ) Contact Microsoft Product Support Services (PSS) for assistance. For information about how to contact PSS, see PSS10R.CHM. Remedy Remove...

[Tested on SharePoint 2016 only] Suppose the following error occurs while creating a new site collection with a farm admin user account: ## Assume all declared variables are correct ## PS C:\FarmAdminUserAccount> New-SPSite -Url $spSite -Name $scName -Description $scDesc -ContentDatabase $cdb -QuotaTemplate $scQuota -Template $scTemplate -Language 1033 -OwnerAlias $scPrimaryAdmin -OwnerEmail $scPrimaryEmail -SecondaryOwnerAlias $scSecondaryAdmin -SecondaryEmail $scSecondaryEmail ********************** PS>CommandInvocation(Out-String): "Out-String" >> ParameterBinding(Out-String): name="InputObject"; value="Calling extension methods on object Microsoft.SharePoint.Administration.SPContentDatabase+<>c__DisplayClass16 failed with exception(s): The UPDATE permission was denied on the object 'MSP_TVF_WEB_ADMIN', database 'WSS_Content_DbName', schema 'pjpub'." New-SPSite : Calling extension methods on object Microsoft.Sha...

[Applies  to SharePoint 2016; not tested on other versions of SharePoint] While the farm account is in the local admins group (regardless of being present in the  WSS_WPG  group), running the psconfigui.exe (SharePoint Configuration Wizard) or psconfig.exe with the farm account gets stuck at the last step (step 10 of 10). Associated behaviors are: CopySideBySideFiles_*.log showing the endless repetition of: “\16\TEMPLATE\LAYOUTS\accessrequestcontrol.debug.js Access is denied. Waiting 30 seconds… Retrying…”. Unable to close the Config Wizard by hitting the Cancel or X button on the GUI; it has to be killed in Task Manager. The “Upgrade Status” page on Central Admin, however, shows the green status “Succeeded” even though it's not. Diagnosis Microsoft has deployed the security hardening with the 2025 September CU. The farm service account can no longer be used interactively from now on. Previously, this was not a requirement, despite the documentation at  https://lear...

[Applies to SharePoint 2016; not tested on other versions of SharePoint] Sometimes you see this false error on Health Analyzer saying that "Account used by application pools or service identities are in the local machine Administrators group": You have confirmed that the reported servers for the “Failing Servers” don’t have the farm account in their local admins group. Script to verify: Foreach($server in (Get-SPServer| ? {$_.Role-NE "Invalid"})) {     $server = $server.ToString().TrimStart("SPServer Name=")     Invoke-Command -ComputerName $server {      Get-LocalGroupMember -Group Administrators      } | select ObjectClass, Name, PrincipalSource, PSComputerName | sort -Property PSComputerName | ft -GroupBy PSComputerName } And yet, hitting the “Reanalyze Now” button does not clear out the error.  Diagnosis The Health Analyzer does not “see” the absence of the farm account in the local admins group until the reported server’s Share...

Symptoms   The Office Online service (WACSM) fails to start from the Services console and PowerShell with this error: The Office Online service on Local Computer started and then stopped. Some service stop sutomatially if they are not in use by other service or programs.   In the Windows Application event logs and as well as sometimes in the Trellix event logs, the following error appears:   ExP:DEP Stack Blocked an attempt to exploit C:\WINDOWS\SYSTEM32\INETSRV\W3WP.EXE   In addition, the Windows Application event logs show:   Service cannot be started. System.InvalidOperationException: The certificate has not been specified .   Even with the Office Online service not running in any of the farm members, OOS still renders Office documents, which is strange. As expected, however, it won’t let you run any Office Online PowerShell commands (e.g. Get-OfficeWebAppsFarm). Causes   Case 1 : A certificate with the same Subject name is found in the Personal Ce...

  Applies to SharePoint 2016; not tested on other versions of SharePoint.   Symptoms   -         CA Health Analyzer shows “ One of the cache hosts in the cluster is down ” and “ One or more services have started or stopped unexpectedly ” errors. -         For the reported server on Health Analyzer, Distributed Cache is shown as “ Status: Online ” on PowerShell and “ Status: Started ” on CA’s “ Services on Server ” page. -         AppFabric Caching Service is stopped on the reported server. When attempted to start, it gives “ Access is denied ”. It doesn’t leave any log entries for the failure in Application or Systems Event logs. -         You verified that the password of the service account that runs the service is correct. Cause   Missing value of connectionString in “ C:\Program Files\AppFabric 1.1 for Windows Server\D...