Add-Member : Cannot add a member with the name "" because a member with that name already exists

Question

When attempting to run script then I got the following the error message.

Error :

Add-Member : Cannot add a member with the name "CAllerID*" because a member with that name already exists. To overwrite the member anyway, add the Force parameter to 
your command.

Script :

    $output = Get-ADUser -Identity user -Properties givenName, sn, displayname, samaccountname, title

$output | Add-Member -membertype noteproperty -name "CAllerID*" -value $null | Export-CSV -Path "c:\tmp\users.csv" -NoTypeInformation -Encoding UTF8

Answer 1

Add -Force and -PassThru to the Add-Member call:

• -Force ensures any existing conflicting properties are overwritten
• -PassThru causes Add-Member to output the modified input object

$output | Add-Member -MemberType NoteProperty -Name "CAllerID*" -Value $null -Force -PassThru | Export-CSV -Path "c:\tmp\users.csv" -NoTypeInformation -Encoding UTF8

If you want to further trim the property set returned by Get-ADUser, use Select-Object:

$output | Select-Object -Property givenName,sn,displayName,SAMAccountName,Title | Add-Member -MemberType NoteProperty -Name "CAllerID*" -Value $null -Force -PassThru | Export-CSV -Path "c:\tmp\users.csv" -NoTypeInformation -Encoding UTF8