Get-AzureRmRecoveryServicesBackupContainer : Requested value 'NotRegistered' was not found - azure

Question

I am using below command in Azure Automation Powershell script to get status of Recovery Services container - it simply checks if a VM is registered for backup.
Get-AzureRmRecoveryServicesVault -Name $AzureRecoveryServicesName | Set-AzureRmRecoveryServicesVaultContext
$BackupStatus = Get-AzureRmRecoveryServicesBackupContainer -ContainerType AzureVM -FriendlyName $VirtualMachineName -ResourceGroupName $ResourceGroupName
If a VM is not registered it throws an error and $BackupStatus is empty:
Get-AzureRmRecoveryServicesBackupContainer : Requested value 'NotRegistered' was not found.
At line:53 char:21
... kupStatus = Get-AzureRmRecoveryServicesBackupContainer -ContainerType ...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CategoryInfo : InvalidArgument: (:) [Get-AzureRmReco...BackupContainer], ArgumentException
FullyQualifiedErrorId :
Microsoft.Azure.Commands.RecoveryServices.Backup.Cmdlets.GetAzureRmRecoveryServicesBackupContainer
And if it is already registered I get $BackupStatus = Microsoft.Azure.Commands.RecoveryServices.Backup.Cmdlets.Models.AzureVmContainer.
I've tried:
$BackupStatus = (Get-AzureRmRecoveryServicesBackupContainer -ContainerType AzureVM -FriendlyName $VirtualMachineName -ResourceGroupName $ResourceGroupName).Status
But then the only difference is that I get $BackupStatus = Registered when VM is already in a container but same error occurs when VM is not registered.
What is the proper way to check if a VM is registered for backup or not? I am ok with what I'm getting - I can handle $BackupStatus values in a script - but I don't want this error message to show.
Strange thing is that in Powershell on PC with same Azure modules versions loaded (AzureRM​.RecoveryServices​.Backup 2.5.0) as in Automation Account I am getting a different behavior:
PS C:\windows\system32> $BackupStatus = Get-AzureRmRecoveryServicesBackupContainer -ContainerType AzureVM -FriendlyName $VirtualMachineName -ResourceGroupName $ResourceGroupName
PS C:\windows\system32> $BackupStatus
Name ResourceGroupName Status ContainerType
---- ----------------- ------ -------------
UbuntuBckptest rhel68128 Registered AzureVM
It returns an object instead of a string.

Answer 1

If you want to set $BackupStatus value according to Get-AzureRmRecoveryServicesBackupContainer command executed result. We could put the Get-AzureRmRecoveryServicesBackupContainer in try...catch.
The following just the code sample
$BackupStatus;
try
{
$BackupStatus=Get-AzureRmRecoveryServicesBackupContainer
}
catch
{
# we can add condition for example : if($BackupStatus.Contains("NotRegistered"))
$BackupStatus = "NotRegistered"
}
# we can add condition :get the type of $BackupStatus for example :if($BackupStatus.GetType().Name.equals("String"))`
$BackupStatus = "Registered"