Backing up of the "Mail flow - Rules" in the "Exchange admin center" - powershell

Question

I need to take a backup of the "Mail flow - Rules" in the "Exchange admin center"
$TransCollect = Export-TransportRuleCollection
$TransCollect1 = [System.Text.Encoding]::Unicode.GetString($TransCollect.FileData)
$TransCollect1 | Set-Content -path c:\temp\2.xml
But I cannot extract anything from the XML file because at the start of the XML file is a special character.
So If run ....
[XML]$AppConfig = Get-Content –Path "c:\temp\2.xml"
I get several errors.
Is there is a problem in the "[System.Text.Encoding]::Unicode.GetString" line itself OR
how do I remove this special character.
See the screenshot for the special character. It shows up at the beginning of the file"

Answer 1

The "special character" you see is the Byte Order Mark for Unicode (aka UTF-16LE) (\xFF\xFE) because you used [System.Text.Encoding]::Unicode.GetString(). To read that file with Get-Content, you need to specify that same encoding using its -Encoding parameter:
[XML]$AppConfig = Get-Content -Path "c:\temp\2.xml" -Encoding Unicode
Depending on the PowerShell version you are using, Get-Content by default uses different encodings:
Versions 5.1 and below use the encoding that corresponds to the system's active code page (usually ANSI)
Versions 6 and up use UTF8NoBOM
Is there a specific reason for writing the XML in UTF16 ? Usually, UTF-8 is used with XML

Answer 2

I was able to use this and bypass the special character entirely as well as getting the EXCHANGE RULES into a extractable format.
$File_Collect = "c:\temp\1.xml"
$TransCollect = Export-TransportRuleCollection
Set-Content -Path $File_Collect -Value $TransCollect.FileData -Encoding Byte
[XML]$TransXMLCollect = Get-Content –Path $File_Collect
$TransXMLCollect.SelectNodes("//rule") | % { $_.InnerText }