Azure PowerShell Get-AzVM returns an error
When using Get-AzVM an error about ‘System.Collections.Generic.IEnumerable’ is returned.
Symptoms
After upgrading to PowerShell 7.3.1 the Get-AzVM cmdlet is failing with an error, even when no parameters are supplied.
1Get-AzVM: GenericArguments[0], 'Microsoft.Azure.Management.Compute.Models.VirtualMachine', on
2'T MaxInteger[T](System.Collections.Generic.IEnumerable`1[T])' violates the constraint of type 'T'.
The version (in my installation) of the cmdlet was 4.31.0. In PowerShell you can check the version of any cmdlet with Get-Command.
1Get-Command Get-AzVM
2
3CommandType Name Version Source
4----------- ---- ------- ------
5Cmdlet Get-AzVM 4.31.0 Az.Compute
Solution
In my case this was fixed by updating the Azure PowerShell modules. You can do this with Update-Module as follows.
1Update-Module Az.*
Once this has completed open a new Powershell session and check the cmdlet has updated using Get-Command
1Get-Command Get-AzVM
2
3CommandType Name Version Source
4----------- ---- ------- ------
5Cmdlet Get-AzVM 5.2.0 Az.Compute
Then check Get-AzVM and you should see it now works and returns the list of Azure Virtual Machines as expected.