Failure retrieving Diagnostics Logs location

I've been getting these Unexpected ULS entries from Timer Job hourly-all-sptimerservice-health-analysis-job:

Failure retrieving Diagnostics Logs location:
System.ArgumentException: Object must be a root directory ("C:\") or a drive letter ("C").
at System.IO.DriveInfo..ctor(String driveName)
at Microsoft.SharePoint.Administration.Health.AppServerDrivesAreNearlyFull. GetDrivesForValidation()

Turns out I had to change Central Administration > Monitoring > Configure diagnostic logging > Path from %CommonProgramFiles%\Microsoft Shared\Web Server Extensions\15\LOGS to C:\Program Files\Common Files\microsoft shared\Web Server Extensions\15\LOGS.

Error is caused by Health Analysis Job (Hourly, Microsoft SharePoint Foundation Timer, All Servers) timer job. Specifically DriveInfo constructor cannot resolve environment variables, so log location has to be a real path.

Alternative Powershell script solution:
$diagSvc = [Microsoft.SharePoint.Administration.SPDiagnosticsService]::Local
$commonProgramFiles = Get-ChildItem -Path Env:\ | where Name -EQ "CommonProgramFiles"
$newLogLocation = $diagSvc.LogLocation.Replace("%CommonProgramFiles%", $commonProgramFiles[0].Value)
$diagSvc.LogLocation = $newLogLocation

$diagSvc.Update()