I am a global administrator and when I run the command Get-AzManagementGroup I get the following error:
Get-AzManagementGroup : The client 'live.com#kellygarcia9@yahoo.co.uk' with object id 'bd24ab44-e034-439e-8a02-756d1e3557a3' does not have authorization to perform action 'Microsoft.Management/managementGroups/read' over scope '/providers/Microsoft.Management' or the scope is invalid. If access was recently granted, please refresh your credentials. At line:1 char:1 + Get-AzManagementGroup + ~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : CloseError: (:) [Get-AzManagementGroup], CloudException + FullyQualifiedErrorId : Microsoft.Azure.Commands.Resources.ManagementGroups.GetAzureRmManagementGroup