powershell error when invoke another script

   I have two scripts that run fine as seperate scripts, but when I invoke one from the other then I get this error message:<br>
"Exception Name: System.Management.Automation.MethodInvocationException
    Exception Type:  
    Exception Message: Exception calling "Open" with "3" argument(s): "Could not find a part of the path 'D:\Data Report\'."

The script being called is moving files from "D:\Data Report\ to another folder in the D:\ directory.
I only get this error when I run the script below. Any ideas?

     try
    {
    $folder = "D:\Data Report\" # Enter the root path you want to monitor.
    $filter = '*.*'  # You can enter a wildcard filter here.
    #$scriptPath = {D:\"file_transfer.ps1"}
 
    # In the following line, you can change 'IncludeSubdirectories to $true if required.                          
    $watcher = New-Object IO.FileSystemWatcher $folder, $filter -Property @{IncludeSubdirectories = $false;NotifyFilter = [IO.NotifyFilters]'FileName, LastWrite'}
 
    Register-ObjectEvent $watcher Created -SourceIdentifier FileCreated -Action {
    $name = $Event.SourceEventArgs.Name
    $changeType = $Event.SourceEventArgs.ChangeType
    $timeStamp = $Event.TimeGenerated
    Write-Host "The file '$name' was $changeType at $timeStamp" -fore green

    #Call the file_transfer.ps1 script
    #Invoke-Expression $scriptPath
    Invoke-Expression D:\file_transfer.ps1
    }

    } # end of try
    catch  #Catch any fatel errors and send an email with description
    {
    $ErrorMessage = $_.Exception.Message
    $FailedItem = $_.Exception.ItemName
    $ErrorName = $_.Exception.GetType().FullName

    $ExceptionBody = @"
    Exception Name: $ErrorName
    Exception Type: $FailedItem
    Exception Message: $ErrorMessage
    "@
    Send-MailMessage  -SmtpServer "server.com" -From "no-replies@company.com" -To "admin@company.com" -Subject "Fatel Error with Monitor Script" -Body $ExceptionBody
    } # end of catch
 
 finally
    {
  
    }