SQL Server 2014 "syspolicy_purge_history" job keeps failing
Can you try this in the Windows Server PowerShell path?

PS C:\Windows\system32&gt; Get-ExecutionPolicy -list

     Scope            ExecutionPolicy
     --------         ------------------
     MachinePolicy    Undefined
     UserPolicy       Undefined
     Process          Undefined
     CurrentUser      Undefined
     LocalMachine     Restricted


..and then the same in the SQL Server path:

PS SQLSERVER:\&gt; Get-ExecutionPolicy -list

     Scope            ExecutionPolicy
     --------         ------------------
     MachinePolicy    Undefined
     UserPolicy       Undefined
     Process          RemoteSigned
     CurrentUser      Undefined
     LocalMachine     Restricted


If the execution policy is set to “Restricted”, try to set it to “RemoteSigned” or “Unrestricted”. 

Set-ExecutionPolicy -Scope LocalMachine -ExecutionPolicy Unrestricted


or  

Set-ExecutionPolicy -Scope LocalMachine -ExecutionPolicy RemoteSigned


Please note that you need to set this execution policy in both the Windows PowerShell and the SQL PowerShell consoles.