Problem with my script, dont execute

Nervill_mcbo I've modified your script to fix the errors that it was throwing for the GetAddressBytes() and the way the array of adapters were listed. 
It is working on my system, so please let me know how it goes now. 

Add-Type -AssemblyName PresentationCore,PresentationFramework

$names = Get-content "C:\Servers.txt"
$subname=" "
$chequea="no"
$dia = Get-date
$ButtonType = [System.Windows.MessageBoxButton]::OK
$MessageIcon = [System.Windows.MessageBoxImage]::Error
$MessageTitle = "Falla de Alcance por Ping"

#$ipV4 = Test-Connection -ComputerName (hostname) -Count 1  | Select -ExpandProperty IPV4Address
$ipsV4 = $(Get-NetAdapter -Physical | where status -eq 'up' | Get-NetIPAddress | where{$_.AddressFamily -eq 'IPv4'}).IPAddress 

#Write-Verbose $ipV4.IPAddressToString
Foreach($ipV4_tmp in $ipsV4) #added due that multiple Adapter could be up
 {
  $ipV4 = $null
  [System.Net.IPAddress]$ipV4 = $ipV4_tmp
  Write-Host $ipV4.IPAddressToString

  If($ipV4_tmp)
   {
    if ($ipV4.GetAddressBytes()[0] -eq "192" -and $ipV4.GetAddressBytes()[1] -eq "168" -and $ipV4.GetAddressBytes()[2] -eq "5" ){
    $chequea="si"
    }
    
    if ($ipV4.GetAddressBytes()[0] -eq "192" -and $ipV4.GetAddressBytes()[1] -eq "168" -and $ipV4.GetAddressBytes()[2] -eq "6" ){
    $chequea="si"
    }
    
    if ($ipV4.GetAddressBytes()[0] -eq "10" -and $ipV4.GetAddressBytes()[1] -eq "212" -and $ipV4.GetAddressBytes()[2] -eq "134" ){
    $chequea="si"
    }
   }
  Else
   {
    Write-Host "Adapter IP item was empty"
   }
 } 

if($chequea -eq "si"){

$Output+="$dia : "
foreach ($name in $names){

 if (Test-Connection -ComputerName $name -Count 1 -ErrorAction SilentlyContinue){
   $Output+= "$name ====>> UP || "
   Write-Host "$name ====>> UP "
   #Write-Verbose "$name ====>> UP "
 }
 else{
    
   $Output+= "$name ====>> DOWN || "
   Write-Host "$name ====>> DOWN "
   #Write-Verbose "$name ====>> DOWN "

   if ($name -eq "8.8.8.8"){
    $subname="DNS Google"
}
   
   if ($name -eq "www.google.com"){
    $subname="Dominio Google"
}
   
   if ($name -eq "192.168.5.1"){
    $subname="Firewall"
}
   
   if ($name -eq "192.168.5.2"){
    $subname="Server 10"
}
   
   if ($name -eq "192.168.5.30"){
    $subname="Server 8"
}
   
   if ($name -eq "192.168.5.29"){
    $subname="Server 9"
}
   
   if ($name -eq "192.168.5.52"){
    $subname="Server 7"
}
   
   if ($name -eq "192.168.6.16"){
    $subname="Server 1"
}
   
   if ($name -eq "192.168.5.94"){
    $subname="Server 2"
}
   
   if ($name -eq "192.168.5.102"){
    $subname="Server 3"
}
   
   if ($name -eq "192.168.5.43"){
    $subname="Server 4"
}
   
   if ($name -eq "192.168.5.124"){
    $subname="Server 5"
}
   
   if ($name -eq "192.168.6.250"){
    $subname="Impresora Wifi"
}
   
   if ($name -eq "192.168.5.250"){
    $subname="Impresora Xerox "
}
   $MessageBody = "Conexion Perdida con el IP: $name, $subname"
   $oReturn=[System.Windows.MessageBox]::Show($MessageBody,$MessageTitle,$ButtonType,$MessageIcon)
 }
  }#foreach
   $Output | Out-file "C:\PingResult.txt" -Append
  }#If