Windows 10 Host, Jenkins Build Permission denied on powershell script modifying file

Question

Hello I am trying to run a powershell script as a build step using MSBuild on jenkins. The script runs fine on local builds, all it does it modify the version number and them saves the file. Set-Content is what is failing.

15:26:28   Set-Content : Access to the path 'D:\Workspaces\SOURCE\ApplicationLabel.h' is denied.
15:26:28   At D:\Workspaces\SOURCE\updateVersion.ps1:64 char:1
15:26:28   + Set-Content -Path ./ApplicationLabel.h -Value $appLabel
15:26:28   + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
15:26:28       + CategoryInfo          : NotSpecified: (:) [Set-Content], UnauthorizedAccessException
15:26:28       + FullyQualifiedErrorId : System.UnauthorizedAccessException,Microsoft.PowerShell.Commands.SetContentCommand

I assumed this was because Jenkins didn't have permission to write. But It is running as a service and still fails.

The script is called in the config as such:

powershell.exe  -NonInteractive -ExecutionPolicy ByPass "& './updateVersion.ps1'

Here is a snippet from the file:

$changeset =Get-LatestChangeset;

$versionString =  "#define BuildVersion L`"$versionNum.$changeset`""

$appLabel = Get-Content -Path ./ApplicationLabel.h
$appLabel = $appLabel -replace '#define BuildVersion L.*"',$versionString


$appLabel = $appLabel -replace '#define BuildDate L.*',$date


Set-Content -Path ./ApplicationLabel.h -Value $appLabel

Is there are readonly setting for workspace source files?