To ensure that our system can effectively handle web traffic, a developer recently set up a new Application Load Balancer using AWS services. However, after configuring the Application Load Balancer, the developer did not register any targets, such as EC2 instances, into the associated target groups. This omission is critical, as the Load Balancer relies on these targets to route incoming traffic to the appropriate destinations.

Given this scenario, which of the following error messages is likely to be generated by the Application Load Balancer due to the absence of registered targets in its target groups?