Attempting to install Exchange Server 2019 to Cumulative Update 7 fails with: “Cannot start service MSExchangeIS on computer”

I do not have many clients with an on-premise Exchange Server but there was one who needed their Exchange Server 2019 CU3 patched to the latest CU7.

Error:

The following error was generated when "$error.Clear();

start-SetupService -ServiceName MSExchangeIS

" was run: "Microsoft.Exchange.Configuration.Tasks.ServiceDisabledException: Service 'MSExchangeIS' is disabled on this server. ---> System.InvalidOperationException: Cannot start service MSExchangeIS on computer '.'. ---> System.ComponentModel.Win32Exception: The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

--- End of inner exception stack trace ---

at System.ServiceProcess.ServiceController.Start(String[] args)

at Microsoft.Exchange.Management.Tasks.ManageSetupService.StartServiceWorker(ServiceController serviceController, String[] serviceParameters)

--- End of inner exception stack trace ---

at Microsoft.Exchange.Configuration.Tasks.Task.ThrowError(Exception exception, ErrorCategory errorCategory, Object target, String helpUrl)

at Microsoft.Exchange.Management.Tasks.ManageSetupService.StartService(ServiceController serviceController, Boolean ignoreServiceStartTimeout, Boolean failIfServiceNotInstalled, Unlimited`1 maximumWaitTime, String[] serviceParameters)

at Microsoft.Exchange.Management.Tasks.ManageSetupService.StartService(String serviceName, Boolean ignoreServiceStartTimeout, Boolean failIfServiceNotInstalled, Unlimited`1 maximumWaitTime, String[] serviceParameters)

at Microsoft.Exchange.Management.Tasks.StartSetupService.InternalProcessRecord()

at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__91_1()

at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".

Attempting to restart the CU7 patch detects the unfinished patching and restarts but then fails again:

There aren’t any Microsoft KBs or blog posts with the error but the message implies the Microsoft Exchange Information Store (MSExchangeIS) could not be started and reviewing the services console does show that it is disabled so I manually enabled it, started it, restarted the installer but it would fail again with the MSExchangeIS service disabled.

A bit of searching on the internet lead me to the following blog post:

https://oddytee.wordpress.com/2017/11/09/cannot-start-service-msexchangeservicehost-on-computer-during-exchange-cu-update/

… which suggested that we chronically change any Microsoft Exchange services set to disabled to automatic with the following PowerShell command:

While (1 -le 2) { Sleep 1 ; Get-Service | Where { $_.DisplayName -Like ‘Microsoft Exchange*’ } | Set-Service –StartupType ‘Automatic’ }

I gave this a shot and can confirm that it allowed CU7 to complete patching the Exchange server.