Update: This behavior was fixed in Skype for Business Server 2015 CU9.

After installing the Skype for Business Server 2015 CU8, we might see the following error when updating the databases on a AlwaysOn BackEnd:

Install-CsDatabase -Update -ConfiguredDatabases -SqlServerFqdn <AlwaysOn SQL Listener>

WARNING: Install-CsDatabase failed.
WARNING: Detailed results can be found at
“C:\Users\Administrator.RECORE\AppData\Local\Temp\2\Install-CsDatabase-e68ceeb8-b8dd-4296-96c6-00d5ec6f96fb.html”.
Install-CsDatabase : Command execution failed: The network path was not found.
At line:1 char:1
+ Install-CsDatabase -Update -ConfiguredDatabases -SqlServerFqdn sqlpool.recore.la …
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [Install-CsDatabase], IOException
+ FullyQualifiedErrorId : ProcessingFailed,Microsoft.Rtc.Management.Deployment.InstallDatabaseCmdlet

Before implementing a workaround, we need to verify if the SfB Back End Databases need to be updated:

Test-CsDatabase -ConfiguredDatabases -SqlServerFqdn <AlwaysOn SQL Listener> | Select SqlServerFqdn, SqlInstanceName, DatabaseName, InstalledVersion, ExpectedVersion | ft -AutoSize

If the expected version matches the installed version, then we don’t need to update the SfB BackEnd database.

In case we need to update the database then we can use this workaround:

Step 1 – Identify the Active SQL Node/Replica

The easiest way to check the current Active SQL Node/Replica, is to use the SQL Management Studio, AlwaysOn High Availability > Availability Replicas:

In this example SQL01 is the active node/replica.

Step 2 – Update the Databases

We need to know which databases are hosted in the BackEnd, for this we can use the SQL Management Studio, Databases:

Or with the Test-CsDatabase PowerShell cmdlet:

Test-CsDatabase -ConfiguredDatabases -SqlServerFqdn <AlwaysOn SQL Listener> | Select SqlServerFqdn, SqlInstanceName, DatabaseName, InstalledVersion, ExpectedVersion | ft -AutoSize

Front End (Red databases):

Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName <SQL Instance> -DatabaseType User
Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName <SQL Instance> -DatabaseType Application

Please note for SQL Default Instance we need to use:

Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName “” -DatabaseType User
Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName “” -DatabaseType Application

Central Management Store (Blue databases):

Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName <SQL Instance> -CentralManagementDatabase

Monitoring (Green databases):

Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName <SQL Instance> -DatabaseType Monitoring

Archiving (Orange database):

Install-CsDatabase -Update -SqlServerFqdn <SQL Active Node/Replica FQDN> -SqlInstanceName <SQL Instance> -DatabaseType Archiving