Cmdlet Copy-Item Fail

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###                                                                         ###
###  Backup Directory                                                       ###
###  ================                                                       ###
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###  This Scipt generates a copy of the differences in                      ###
###  in relation to a directory and a backup directory.                     ###
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###  The script needs two arguments to run:                                 ###
###  $args[0] = path of folder to copy (just files inside get copied)       ###
###  $args[1] = path of destination to save copied files of the folder      ###
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<#'if ($args.Length -lt 2) {exit} # Wrong call of the script 

$pathCopy = $args[0]
$pathDest = $args[1]

if (-not (Test-Path -Path $pathCopy) -or -not (Test-Path -Path $pathDest)) {exit} # Wrong path#>


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#                                       Copy the differences


# Find Files existing for both directories
$filesCopy = Get-ChildItem -Path $pathCopy -File -Recurse -Force | 
                select -Property @{Name='CommonName';Expression={$_.FullName.Replace("$pathCopy\",'')}}  
$filesDest = Get-ChildItem -Path $pathDest -File -Recurse -Force | 
                select -Property @{Name='CommonName';Expression={$_.FullName.Replace("$pathDest\",'')}}  

$files = @()

if ($filesCopy -eq $null) {$filesCopy = @()}
if ($filesDest -eq $null) {$filesDest = @()}


# Files that exist in both folders
$temp = compare -ReferenceObject $filesCopy -DifferenceObject $filesDest -Property CommonName -IncludeEqual -ExcludeDifferent | 
            select -Property @{Name='FullNameCopy';Expression={"$pathCopy\$($_.CommonName)"}}, `  
                             @{Name='FullNameDest';Expression={"$pathDest\$($_.CommonName)"}}  


# Filter only files that got changed
if ($temp -ne $null) 
{
    $files += $temp | foreach `
                {
                    if ((Get-Item -Path $_.FullNameCopy -Force).LastWriteTimeUtc.ToString() -ne (Get-Item -Path $_.FullNameDest -Force).LastWriteTimeUtc.ToString()) {$_}
                }
}


# Files that exist just in the folder to copy
$temp = compare -ReferenceObject $filesCopy -DifferenceObject $filesDest -Property CommonName | 
            where {$_.SideIndicator -eq '<='} |   
                select -Property @{Name='FullNameCopy';Expression={"$pathCopy\$($_.CommonName)"}}, `  
                                 @{Name='FullNameDest';Expression={"$pathDest\$($_.CommonName)"}}  


if ($temp -ne $null) {$files += $temp}



# Copy files
$files | foreach {
    if (-not (Split-Path -Path $_.FullNameDest -Parent | Set-Variable -Name temp -PassThru | select -ExpandProperty Value | Test-Path)) 
    {
        New-Item -Path (Split-Path -Path $temp -Parent) -Name (Split-Path -Path $temp -Leaf) -ItemType Directory -Force
    };
    if (Test-Path -Path $_.FullNameDest) {
        Set-ItemProperty -Path $_.FullNameDest -Name IsReadOnly -Value $false
    };
    Copy-Item -Path $_.FullNameCopy -Destination $temp -Force;
    Set-ItemProperty -Path $_.FullNameDest -Name LastWriteTimeUtc -Value (Get-ItemProperty -Path $_.FullNameCopy -Name LastWriteTimeUtc | select -ExpandProperty LastWriteTimeUtc) -Force;
    Set-ItemProperty -Path $_.FullNameDest -Name IsReadOnly -Value $true
}