NM: Error running PowerShell - "The term 'Get-Mailbox' is not recognized as the name of a cmdlet" (4312115)

Issue

We are seeing the following error when we try to match a user via PowerShell:

Transcript started, output file is c:\logs\PSLOG_20141002-09-17-25.log 
Get-Mailbox : The term 'Get-Mailbox' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again. 
At C:\logs\BTUserMatching.ps1:37 char:18 + $user=Get-Mailbox jsmith@acme.com + CategoryInfo : ObjectNotFound: (Get-Mailbox:String) [], Command NotFoundException + FullyQualifiedErrorId : CommandNotFoundException

Solution

Configure the Notes Migrator Settings - 'User Provisioning' tab, to use Remote PowerShell, and use the correct PowerShell URL.
For on-prem migrations, it should be the CAS server Fully Qualified Name.
For O365 the URL should be  https://ps.outlook.com/powershell  or https://outlook.office365.com/powershell