ScanUnsupportedChars script for Azure File Sync kicks error: Add-Type -ReferencedAssemblies $assemblies -TypeDefinition @"

Downloaded code and when trying to run per example, kicked the following error:

PS> ./ScanUnsupportedChars.ps1 -SharePath \\sync.contoso.com\share -CsvPath C:\temp\unsupportedchars
Add-Type: C:\Users\xx\Downloads\azure-files-samples-master\azure-files-samples-master\ScanUnsupportedChars\ScanUnsupportedChars.ps1:130
Line |
130 | Add-Type -ReferencedAssemblies $assemblies -TypeDefinition @"
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| (8,14): error CS0234: The type or namespace name 'Linq' does not exist in the namespace 'System' (are you
| missing an assembly reference?) using System.Linq; ^

server name changed above for posting.

Any idea how I can resolve this?