Worked perfectly; thank you!

2017-03-16 09:02:06 AM (UTC-05:00) Test01.txt was transferred to /PosPayPut/.
2017-03-16 09:02:06 AM (UTC-05:00) Test02.txt was not transferred to /PosPayPut/. Error: Can't open file 'H:\Documents\PositivePay\Test02.txt'. System Error. Code: 5. Access is denied.
2017-03-16 09:02:07 AM (UTC-05:00) Test03.txt was transferred to /PosPayPut/.
2017-03-16 09:02:07 AM (UTC-05:00) Test04.txt was not transferred to /PosPayPut/. Error: Can't open file 'H:\Documents\PositivePay\Test04.txt'. System Error. Code: 5. Access is denied.
2017-03-16 09:02:07 AM (UTC-05:00) Test05.txt was transferred to /PosPayPut/.
2017-03-16 09:02:08 AM (UTC-05:00) Test07.txt was transferred to /PosPayPut/.
2017-03-16 09:02:08 AM (UTC-05:00) Test09.txt was transferred to /PosPayPut/.

The $Transfer.Error.Message is incorrect.

Use $Transfer.Failures[0].Message

See https://winscp.net/eng/docs/library_transferoperationresult

After reading about "Automating download in parallel connections over SFTP/FTP protocol", I was able to adapt my script and I got the error handling to work for each $FilePath in $FilePaths.

The remaining issue to be resolved is how to capture the $Transfer.Error.Message. When I run the script below in PS ISE, I get the results that I want, except that the error part is blank.

Here is was appears in the console:
2017-03-14 04:31:43 PM (UTC-05:00) Test01.txt was transferred to /PosPayPut/.
2017-03-14 04:31:43 PM (UTC-05:00) Test02.txt was not transferred to /PosPayPut/. Error: .
2017-03-14 04:31:43 PM (UTC-05:00) Test03.txt was transferred to /PosPayPut/.
2017-03-14 04:31:43 PM (UTC-05:00) Test04.txt was not transferred to /PosPayPut/. Error: .
2017-03-14 04:31:44 PM (UTC-05:00) Test05.txt was transferred to /PosPayPut/.
2017-03-14 04:31:44 PM (UTC-05:00) Test07.txt was transferred to /PosPayPut/.
2017-03-14 04:31:44 PM (UTC-05:00) Test09.txt was transferred to /PosPayPut/.

Here is my revised code:

Yes, that's correct.

(You have to login).

Thank you for the reply.

As I understand it, when an error is encountered, the script stops immediately (by design). Therefore, the script doesn't loop through each $transfer in $transferResult.Transfers. That's why the code below only lists the first failed file and not the others. Is that correct?

else
{
Write-Host ("Upload of {0} failed: {1}" -f
$transfer.FileName, $transfer.Error.Message)
}

(Also, as an aside comment, I registered online for a username, but when I try to post a comment, I get a red box that says:
"Sorry, but this username has already been taken." I am not sure why it won't let me post under my username: sjham)

That's the expected behavior.

If you need different error handling, you have to transfer the files one-by-one.
See https://winscp.net/eng/docs/library_example_recursive_download_custom_error_handling (it's for download though)

I am new at PowerShell, and I am using the automated script to upload files to an FTP site.
In order to test for failures, I created five text files and removed the permissions from two of them so that the error message would be:
Can't open file 'H:\Documents\PositivePay\Test02.txt'.

Test Files:
Test01
Test02 (Permissions Removed; Properties > Security > Advanced > Change Permissions > Uncheck "Include..." > Remove > Apply)
Test03
Test04 (Permissions Removed; Properties > Security > Advanced > Change Permissions > Uncheck "Include..." > Remove > Apply)
Test05

When uploading all five files at once, I would expect to see:

Upload of H:\Documents\PositivePay\Test01.txt succeeded, moving to backup
Upload of H:\Documents\PositivePay\Test02.txt failed: Can't open file 'H:\Documents\PositivePay\Test02.txt'.
System Error. Code: 5.
Access is denied
Upload of H:\Documents\PositivePay\Test03.txt succeeded, moving to backup
Upload of H:\Documents\PositivePay\Test04.txt failed: Can't open file 'H:\Documents\PositivePay\Test02.txt'.
System Error. Code: 5.
Access is denied
Upload of H:\Documents\PositivePay\Test03.txt succeeded, moving to backup

However, instead the following happens:
Only the first file (Test01) is uploaded.
Only the first error (Test02) is displayed.

Nothing happens to Test03, Test04 or Test05.

From the Console:
Upload of H:\Documents\PositivePay\Test01.txt succeeded, moving to backup
Upload of H:\Documents\PositivePay\Test02.txt failed: Can't open file 'H:\Documents\PositivePay\Test02.txt'.
System Error. Code: 5.
Access is denied

Here is the script.

param (
$localPath = "H:\Documents\PositivePay\",
$remotePath = "/PosPayPut",
$backupPath = "H:\Documents\BMOSFTP\Backup"
)

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

# Setup session options
$sessionOptions = New-Object WinSCP.SessionOptions -Property @{
Protocol = [WinSCP.Protocol]::Sftp
HostName = "INTENTIONALLY BLANK"
UserName = "INTENTIONALLY BLANK"
Password = "INTENTIONALLY BLANK"
SshHostKeyFingerprint = "ssh-rsa 1024 xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx"
}

$session = New-Object WinSCP.Session

try
{
# Connect
$session.Open($sessionOptions)

# Upload files, collect results
$transferResult = $session.PutFiles($localPath, $remotePath)

# Iterate over every transfer
foreach ($transfer in $transferResult.Transfers)
{
# Success or error?
if ($transfer.Error -eq $Null)
{
Write-Host ("Upload of {0} succeeded, moving to backup" -f
$transfer.FileName)
# Upload succeeded, move source file to backup
Move-Item $transfer.FileName $backupPath
}
else
{
Write-Host ("Upload of {0} failed: {1}" -f
$transfer.FileName, $transfer.Error.Message)
}
}
}
finally
{
# Disconnect, clean up
$session.Dispose()
}

#exit 0
}
catch [Exception]
{
Write-Host ("Error: {0}" -f $_.Exception.Message)
#exit 1
}