Error running Powershell script in Centos72 with powershell 6 installed - powershell

Question

I have a powershell script to delete a folder on a bunch of Windows hosts in our cluster.
It runs fine in the ISE and when running local from my laptop. however, I installed powershell on my Centos7.2 machine and when I try to run I get the following error
Join-Path : Cannot process argument because the value of argument "drive" is
null. Change the value of argument "drive" to a non-null value.
At /home/user/powershell/delete_.file.ps1:11 char:20
+ $newfilepath = Join-Path "\\$computer" "$file"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Join-Path],
PSArgumentNullException
+ FullyQualifiedErrorId :
ArgumentNull,Microsoft.PowerShell.Commands.JoinPathCommand
Test-Path : Cannot bind argument to parameter 'Path' because it is null.
At /home/user/powershell/delete_.file.ps1:12 char:19
+ if (test-path $newfilepath) {
+ ~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Test-Path],
ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.TestPathCommand
here is the code to the script
$filelist = #("C$\.file")
$computers = Get-Content /home/user/powershell/sw_win.txt
foreach ($file in $filelist)
{
foreach ($computer in $computers)
{
Write-Host -ForegroundColor Yellow "Analysing $computers"
$newfilepath = Join-Path "\\$computer" "$file"
if (test-path $newfilepath) {
Write-Host "$newfilepath Folder exists"
try
{
Remove-Item $newfilepath -Force -recurse -ErrorAction Stop
}
catch
{
Write-host "Error while deleting $newfilepath on $computer.
`n$($Error[0].Exception.Message)"
}
Write-Host "$newfilepath folder deleted"
} else {
Write-Information -MessageData "Path $newfilepath does not exist"
}
}
}
I think its because $computer is not set, but what doesn't make sense is it works fine using ISE.
Any help would be appreciated