how to fix You do not have permissions to create resource groups under subscription

Please provide more information about your situation. The error itself indicates you do not have the necessary permissions in Azure for your subscription to create resource groups. Someone with admin rights in your subscription would need to grant you permissions to create resource groups as discussed here.

You used a tag of Azure Resource Mover which leads me to believe that there is more to your situation then just a simple permissions issue but without further details we'd only be guessing.

IAM at the subscription level settings are as follows:

Current Role Assignments -> Classic Administrator -> Service Administrator ->

Has full access to all resources in the subscription.

I am still unable to create a resource group to deploy Azure resources in.

That was the only tag available that was close to my situation.

I did until yesterday. I wonder if this has anything to do with this (see below):

Transition to role-based access control (RBAC) in Azure by 31 August 2024

You're receiving this notice because you use Azure classic administrator roles.

On 31 August 2024, Azure classic administrator roles will be retired. If your organization has active Co-Administrator or Service Admin roles, you'll need to transition to using Azure RBAC roles by then. (All Azure classic resources and Azure Service Manager will also be retired on that date.)

You may continue using these Azure classic admin roles until they're retired. However, starting 3 April 2024, you'll no longer be able to add new Co-Administrator roles through the Azure portal.