Cannot convert argument "0", with value: "002374E4DBEC", for "LaunchClientApplication" to type "WebServiceProxy.ExternalId": "Cannot convert the "002374E4DBEC" value of type "System.String" to type "WebServiceProxy.ExternalId"."
At C:PowerShellScriptsCrawler.ps1:72 char:50
+     $guid = $OSSNBranchWS.LaunchClientApplication <<<< ($FTCSTBExternalID.Ext_Device_ID,$applicationUri)
    + CategoryInfo          : NotSpecified: (:) [], MethodException
    + FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument

### Crawler

### SQL Login
$SQLUser = "USERNAME"
$SQLPassword = "PASSWORD"

$SQLServer = "SQLSERVERDB"
$SQLDBName = "SQLDB"

$SqlQuery = "select a.externalID as Acct_Number, d.externalId as Ext_Device_ID
from bm_account a inner join
    bm_device d on a.accountId = d.accountId
where a.externalId='9999999999'
order by Acct_Number,Ext_Device_ID"

$SqlConnection = New-Object System.Data.SqlClient.SqlConnection
$SqlConnection.ConnectionString = "Server = $SQLServer; Database = $SQLDBName; User ID = $SQLUser; Password = $SQLPassword;"

$SqlCmd = New-Object System.Data.SqlClient.SqlCommand
$SqlCmd.CommandText = $SqlQuery
$SqlCmd.Connection = $SqlConnection

$SqlAdapter = New-Object System.Data.SqlClient.SqlDataAdapter
$SqlAdapter.SelectCommand = $SqlCmd

$DataSet = New-Object System.Data.DataSet
$rowCount = $SqlAdapter.Fill($DataSet)

$SqlConnection.Close()

$FTCSTBExternalIDs = $DataSet.Tables[0]

$Domain = 'DM'
$UserName = 'USERNAME'
$Password = 'PASSWORD'

$UsernameDomain = $Domain+''+$UserName

$SecurePassword=ConvertTo-SecureString -String $Password -AsPlainText -Force

$Credential = New-Object System.Management.Automation.PSCredential $UsernameDomain,$SecurePassword

$OSSNBranchWS = New-WebServiceProxy -Uri "http://mediaroomserver/ossNotificationsWS/UI.asmx?wsdl" -Namespace WebServiceProxy -Credential $Credential

$applicationUri = "page:http://mediaroomserver.com/FTCPFApps/STBScrollingMessages/MediaroomPage.aspx"

ForEach ($FTCSTBExternalID in $FTCSTBExternalIDs)
{
    $msg_time = Get-Date -UFormat "%Y-%m-%d %r"
    $message = $msg_time+' - FTC Account Number: "'+$FTCSTBExternalID.Acct_Number+'", Device ID: "'+$FTCSTBExternalID.Ext_Device_ID+'"' | Out-File $log_file -Append

    $guid = $OSSNBranchWS.LaunchClientApplication($FTCSTBExternalID.Ext_Device_ID,$applicationUri)
}