GCE Windows Startup script failing with parsing errors - google-cloud-storage

Question

I have a PowerShell script in one of the GCS buckets. I configured a GCE instance to use this as the startup script. This GCE instance has service accounts and has the necessary API access. However, when the script starts running, I see parsing errors. I can run the script locally without any issues. This happens only when I use that from a GCS bucket. If I put the script as a Github gist, it runs perfectly as well.
Here is what I see in the serial console log.
2018/02/27 18:08:25 GCEMetadataScripts: Starting startup scripts (version 4.1.6#1).
2018/02/27 18:08:42 GCEMetadataScripts: Found windows-startup-script-url in metadata.
2018/02/27 18:10:09 windows-startup-script-url: At C:\Windows\TEMP\metadata-scripts968189735\windows-startup-script-url.ps1:2
2018/02/27 18:10:09 windows-startup-script-url: char:9
2018/02/27 18:10:09 windows-startup-script-url: + "error": {
2018/02/27 18:10:09 windows-startup-script-url: + ~
2018/02/27 18:10:09 windows-startup-script-url: Unexpected token ':' in expression or statement.
2018/02/27 18:10:09 windows-startup-script-url: At C:\Windows\TEMP\metadata-scripts968189735\windows-startup-script-url.ps1:3
2018/02/27 18:10:09 windows-startup-script-url: char:11
2018/02/27 18:10:09 windows-startup-script-url: + "errors": [
2018/02/27 18:10:09 windows-startup-script-url: + ~
2018/02/27 18:10:09 windows-startup-script-url: Unexpected token ':' in expression or statement.
2018/02/27 18:10:09 windows-startup-script-url: At C:\Windows\TEMP\metadata-scripts968189735\windows-startup-script-url.ps1:5
2018/02/27 18:10:09 windows-startup-script-url: char:13
2018/02/27 18:10:09 windows-startup-script-url: + "domain": "global",
2018/02/27 18:10:09 windows-startup-script-url: + ~
2018/02/27 18:10:09 windows-startup-script-url: Unexpected token ':' in expression or statement.
2018/02/27 18:10:09 windows-startup-script-url: At C:\Windows\TEMP\metadata-scripts968189735\windows-startup-script-url.ps1:11
2018/02/27 18:10:10 windows-startup-script-url: char:4
2018/02/27 18:10:10 windows-startup-script-url: + ],
2018/02/27 18:10:10 windows-startup-script-url: + ~
2018/02/27 18:10:10 windows-startup-script-url: Missing argument in parameter list.
2018/02/27 18:10:10 windows-startup-script-url: + CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordEx
2018/02/27 18:10:10 windows-startup-script-url: ception
2018/02/27 18:10:10 windows-startup-script-url: + FullyQualifiedErrorId : UnexpectedToken
2018/02/27 18:10:10 windows-startup-script-url:
2018/02/27 18:10:10 GCEMetadataScripts: windows-startup-script-url exit status 1
2018/02/27 18:10:10 GCEMetadataScripts: Finished running startup scripts.
Here is the startup script.
[DscLocalConfigurationManager()]
Configuration GCEDscMetaConfig
{
param
(
[Parameter(Mandatory = $true)]
[String]
$RegistrationUrl,
[Parameter(Mandatory = $True)]
[String]
$RegistrationKey,
[Parameter(Mandatory = $true)]
[String[]]
$ConfigurationNames
)
Node localhost
{
Settings
{
RefreshMode = 'Pull'
}
ConfigurationRepositoryWeb AzureAutomationDSC
{
ServerUrl = $RegistrationUrl
RegistrationKey = $RegistrationKey
ConfigurationNames = $ConfigurationNames
}
ResourceRepositoryWeb AzureAutomationDSC
{
ServerUrl = $RegistrationUrl
RegistrationKey = $RegistrationKey
}
ReportServerWeb AzureAutomationDSC
{
ServerUrl = $RegistrationUrl
RegistrationKey = $RegistrationKey
}
}
}
$Params = #{
RegistrationUrl = 'https://pullserver/accounts/7471b7ce-95d2-4766-be97-221f4d33f56a'
RegistrationKey = 'ljey=='
ConfigurationNames = 'webserver.localhost'
OutputPath = "$env:TEMP\MetaConfig"
}
GCEDscMetaConfig #Params
Set-DscLocalConfigurationManager -Path "$env:TEMP\MetaConfig" -Verbose
This is just a DSC meta configuration script.
Any idea what I am missing here?