Failed Exchange setup recovery checklist

Symptoms to confirm

• Setup stops within seconds with one of these combinations, followed by a pointer to the setup log:

Setup previously failed while performing the action "Install". You can't resume setup by performing the action "BuildToBuildUpgrade".

Setup previously failed while performing the action "BuildToBuildUpgrade". You can't resume setup by performing the action "Install".

Setup previously failed while performing the action "BuildToBuildUpgrade". You can't resume setup by performing the action "Uninstall".

The Exchange Server setup operation didn't complete. More details can be found in ExchangeSetup.log located in the <SystemDrive>:\ExchangeSetupLogs folder.

• A related readiness check can fail instead, once for each affected role (the role name varies): A Setup failure previously occurred while installing the HubTransportRole role. Either run Setup again for just this role, or remove the role using Control Panel.
• The server usually still shows the side effects of the first failure: Exchange services stopped and set to Disabled, a retry that ends with Cannot start the service Microsoft Exchange Service Host, Outlook on the web errors, no mail flow, or components left Inactive (see Exchange components stuck Inactive after an update).

Likely causes

As setup works through each role, it records its progress in the registry under HKLM\SOFTWARE\Microsoft\ExchangeServer\v15\<Role>, for example MailboxRole, ClientAccessRole or HubTransportRole:

• Action: what setup was doing, such as Install, BuildToBuildUpgrade (setup's name for a CU upgrade) or Uninstall.
• Watermark: the last step it completed.

Checklist

1. 1

   Find the real failure

   The message only tells you that an earlier run failed; the reason is in C:\ExchangeSetupLogs\ExchangeSetup.log. Read the last errors, or let the SetupLogReviewer script from Microsoft's CSS-Exchange project match them against known issues:

   powershell

   Select-String -Path 'C:\ExchangeSetupLogs\ExchangeSetup.log' -Pattern '\[ERROR\]' |
     Select-Object -Last 15 | ForEach-Object Line
   .\SetupLogReviewer.ps1 -SetupLog 'C:\ExchangeSetupLogs\ExchangeSetup.log'

2. 2

   Fix that cause

   Typical culprits are services that wouldn't stop (restart the server before setup), antivirus interference (apply the documented exclusions or turn it off during setup), a pending restart or missing prerequisite (Exchange setup prerequisite errors) and Active Directory preparation (PrepareSchema and PrepareAD errors).

3. 3

   See what setup recorded

   powershell

   Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\ExchangeServer\v15' |
     ForEach-Object { Get-ItemProperty -Path $_.PSPath } |
     Where-Object { $_.Action -or $_.Watermark } |
     Select-Object PSChildName, Action, Watermark

4. 4

   Resume with the same action and the same media

   Restart the server, mount the ISO you originally used and run setup from an elevated prompt with an explicit path. A bare setup.exe in PowerShell can start the older copy in the Exchange Bin folder instead.

   cmd

   D:\Setup.exe /Mode:Upgrade /IAcceptExchangeServerLicenseTerms_DiagnosticDataOFF

   If setup can't even start because services are Disabled (Cannot start the service Microsoft Exchange Service Host), restore the services that were running before the update, rename C:\ExchangeSetupLogs (for example to ExchangeSetupLogs-OLD) as Microsoft's troubleshooting article advises, then run the upgrade command again:

   powershell

   Set-Location (Join-Path $env:ExchangeInstallPath 'Bin')
   Add-PSSnapin -Name Microsoft.Exchange.Management.PowerShell.Setup -ErrorAction SilentlyContinue
   .\ServiceControl.ps1 AfterPatch
   Get-Service -DisplayName 'Microsoft Exchange*' | Format-Table DisplayName, StartType, Status

5. 5

   Last resort: clear the watermark

   If you genuinely can't complete the recorded action (for example, you must uninstall a server whose upgrade can't be finished), the widely used community workaround is to back up the role key, delete its Action and Watermark values and run setup again so it starts that role from the beginning:

   powershell

   reg export 'HKLM\SOFTWARE\Microsoft\ExchangeServer\v15\MailboxRole' "$env:USERPROFILE\MailboxRole-backup.reg"
   Remove-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\ExchangeServer\v15\MailboxRole' -Name Action, Watermark

Watch out: Don't delete the Exchange server object in ADSI Edit or rebuild the machine just to get past this message. The server object holds configuration that databases, connectors and certificates depend on. If a server is truly lost, rebuild it with the same name and use Setup.exe /Mode:RecoverServer instead.

Verify

• Setup ends with The Exchange Server setup operation completed successfully. Restart the server afterwards.
• The registry query from step 3 returns nothing.
• The file version matches the build you installed: Get-Command ExSetup.exe | ForEach-Object { $_.FileVersionInfo }.
• Test-ServiceHealth shows RequiredServicesRunning : True for every role, and Get-ServerComponentState $env:COMPUTERNAME | Where-Object State -ne 'Active' lists only ForwardSyncDaemon and ProvisioningRps, which are normally Inactive on-premises.
• You've installed the latest Security Update for the new CU (installing Exchange security updates) and the Health Checker comes back clean.

Prevent it next time

• Restart the server before every CU, run setup elevated with an explicit path, and keep antivirus exclusions in place.
• Run Health Checker and SetupAssist (aka.ms/ExSetupAssist) beforehand; they catch pending restarts and AD problems early.
• Patch one server at a time in maintenance mode (patching a DAG without downtime).
• Keep the ISO of the installed CU; repairs and some update errors ask for the original media.