:Why does the system prompt the following error message when I create a VPC firewall for my CEN instance: It is not allowed to be created because of the existing unauthorized network instance?

We recommend that you grant permissions on the VPC to Cloud Firewall or upgrade Cloud Firewall to Ultimate Edition before you create a VPC firewall. To grant the permissions, use your Alibaba Cloud account to log on to the Cloud Firewall console. For more information, see Authorize Cloud Firewall to access other cloud resources and Upgrade and downgrade Cloud Firewall.

• Before you create a VPC firewall for your CEN instance, we recommend that you have knowledge of the use scenarios, limits, and prerequisites of Cloud Firewall. For more information, see Configure a VPC firewall for an Enterprise Edition transit router and Configure a VPC firewall for a Basic Edition transit router.

• If a VPC that belongs to another Alibaba Cloud account is attached to your CEN instance, and you have purchased Cloud Firewall Enterprise Edition or Ultimate Edition, the VPC supports firewalls created in Cloud Firewall even if the Alibaba Cloud account of the VPC has not purchased Cloud Firewall Enterprise Edition or Ultimate Edition. VPC firewalls are supported only if the Alibaba Cloud account of the CEN instance has purchased Cloud Firewall Enterprise Edition or Ultimate Edition.