Getting exception while running Set-AzureVMCustomScriptExtension

We are using custom script extension to remotely download and execute azure PowerShell script on azure VM. It was running but since yesterday evening we are getting below exception while runningSet-AzureVMCustomScriptExtensionon our build server(perhaps after deploying a cloud service from that server) :

 Get-AzureVM-ServiceName$AzureServiceName-Name$AzureSubServiceName| Set-AzureVMCustomScriptExtension-StorageAccountName $AzureStorageAccount-ContainerName $AzureStorageContainer-FileName $ZipFileName, $DeployScriptFileName, $WebServiceProfileName-Run $DeployScriptFileName-Argument"$ZipFileName$WebSiteRootPath$WebServiceProfileName$PowershellLogPath$UnZipLocationOnVM"|

Update-AzureVM   

Getting below exception while trying to execute red highlighted line :

Caught an exception while downloading the files

Exception Type: System.Management.Automation.CmdletInvocationException

Exception Message: A cmdlet named 'Add-AzureCacheWorkerRole' already exists. Cmdlets must have unique names.

Thanks & Regards

Gaurav