Microsoft Azure is a cloud computing service - meaning that, it is a software, which allow us to manage resources at Microsoft cloud datacenters (cloud farms) around the world.
When we manage our resources then we actually connect to a service named Azure Resource Manager. Azure Resource Manager provides a management layer that enables us to create, update, and delete resources in our Azure account. This service first authenticates and authorizes any request we send to the Azure regarding changing in resources. Next, it sends the request to the right Azure service.
You can read more about Azure Resource Manager here: https://docs.microsoft.com/en-us/azure/azure-resource-manager/management/overview
In order to manage different types of resources the Azure Resource Manager uses different providers according to the resource we manage these called Azure resource providers.
For example, if you deploy SQL Server Virtual Machine then the Azure Resource Manager uses Azure resource provider named Microsoft.SqlVirtualMachine and when you manage store keys and secrets, then you work with the Microsoft.KeyVault resource provider.
Before using the relevant resource provider in order to manage Azure Service, the Azure subscription must be registered for the resource provider. Some resource Providers are registered by default while other resource providers are registered automatically by the Azure Resources Manager when we take certain actions.
Some actions (like changes in the subscription type) might lead to an issue in the registration of Azure Resource Provider(s). The user can not use a resource providers that aren't registered. Therefore, in this case we might get the error:
The subscription is not registered to use
We can register an Azure Resource Provider manually and fix this issue.
(1) navigate to the Azure Portal list of subscription: https://portal.azure.com/#blade/Microsoft_Azure_Billing/SubscriptionsBlade
(2) Click on the relevant subscription
(3) On the left menu click on `Resource Providers`
(4) Select the relevant Resource Provider
(5) On the top of the page, Click on Register if the resource provider is not registered or use the option re-register if it is already seems like it is registered.
You should see the status changed to
This should solve the issue.
Read more - recommended