TransferSupport.State set to "On", but exits upon error

Upload of FILENAME HERE failed: WinSCP.SessionRemoteException: Error transferring file 'FILENAME HERE'.
Copying files to remote side failed.
Unexpected error encountered. Please retry.
Permissions of  kept with their defaults
Timestamp of  kept with its default (current time)
Error: Exception calling "Check" with "0" argument(s): "Error transferring file 'FILENAME HERE'.
Copying files to remote side failed.
Unexpected error encountered. Please retry."

# Load WinSCP .NET assembly
Add-Type -Path "WinSCPnet.dll"

# Session.FileTransferred event handler
 
function FileTransferred
{
    param($e)
 
    if ($e.Error -eq $Null)
    {
        Write-Host "Upload of $($e.FileName) succeeded"
    }
    else
    {
        Write-Host "Upload of $($e.FileName) failed: $($e.Error)"
    }
 
    if ($e.Chmod -ne $Null)
    {
        if ($e.Chmod.Error -eq $Null)
        {
            Write-Host "Permissions of $($e.Chmod.FileName) set to $($e.Chmod.FilePermissions)"
        }
        else
        {
            Write-Host "Setting permissions of $($e.Chmod.FileName) failed: $($e.Chmod.Error)"
        }
 
    }
    else
    {
        Write-Host "Permissions of $($e.Destination) kept with their defaults"
    }
 
    if ($e.Touch -ne $Null)
    {
        if ($e.Touch.Error -eq $Null)
        {
            Write-Host "Timestamp of $($e.Touch.FileName) set to $($e.Touch.LastWriteTime)"
        }
        else
        {
            Write-Host "Setting timestamp of $($e.Touch.FileName) failed: $($e.Touch.Error)"
        }
 
    }
    else
    {
        # This should never happen during "local to remote" synchronization
        Write-Host "Timestamp of $($e.Destination) kept with its default (current time)"
    }
}

function FileTransferProgress
{
    param($e)

    Write-Progress `
        -Id 1 -Activity $e.FileName -Status ("{0:P0} complete:" -f $e.FileProgress) `
        -PercentComplete ($e.FileProgress * 100)
}


try
{
    # Set up session options
    $sessionOptions = New-Object WinSCP.SessionOptions -Property @{
        "sessionOptions here" = ""
    }
 
    $session = New-Object WinSCP.Session
    try
    {
        # Will continuously report progress of synchronization
        $session.add_FileTransferred( { FileTransferred($_) } )

        # Will continuously report progress of transfer
        $session.add_FileTransferProgress( { FileTransferProgress($_) } )
 
        # Connect
        $session.Open($sessionOptions)

        $transferOptions = New-Object WinSCP.TransferOptions
        $transferOptions.ResumeSupport.State = [WinSCP.TransferResumeSupportState]::On
 
        # Synchronize files
        $synchronizationResult = $session.SynchronizeDirectories(
            [WinSCP.SynchronizationMode]::Remote,    #Remote is synced to match local
            "LOCAL", #Local repository
            "REMOTE",           #Remote repository
            $True,                                   #Delete remove files not in local repository  
            $False,                                  #Do not sync in mirror mode
            [WinSCP.SynchronizationCriteria]::Time,  #Sync based on timestamp
            $transferOptions
            )
 
        # Throw on any error
        $synchronizationResult.Check()
    }
    finally
    {
        # Disconnect, clean up
        $session.Dispose()
    }
 
    exit 0
}
catch
{
    Write-Host "Error: $($_.Exception.Message)"
    exit 1
}