Set-ADUser : Cannot find an object with identity: 'a-kpolamara' under: 'DC=noam,DC=cemexnet,DC=com'.

Import-Module ActiveDirectory
$filepath=Read-Host -Prompt "Please enter the CSV path"
$Users = Import-Csv $filepath
foreach($User in $Users){
    $CemexID = $_.sAMAccountName

    $Department = $_.department
Set-ADUser $User.sAMAccountName -department $User.department
}