这个错误通常是因为 terraform 的 ECS Provider 不支持使用 load balancer 参数。解决方法可能是手动编写 load balancer 的资源，并将其与 ECS 实例集成。以下是一个示例：

resource "aws_lb" "example" {
  name = "example-load-balancer"
  internal = false
  load_balancer_type = "application"
  security_groups = [
    aws_security_group.example_sg.id
  ]
  subnets = [
    aws_subnet.example_subnets[0].id,
    aws_subnet.example_subnets[1].id
  ]
}

resource "aws_lb_listener" "example" {
  load_balancer_arn = aws_lb.example.arn
  port = "80"
  protocol = "HTTP"

  default_action {
    target_group_arn = aws_alb_target_group.example.arn
    type = "forward"
  }
}

resource "aws_alb_target_group" "example" {
  name = "example-target-group"
  port = "80"
  protocol = "HTTP"
  vpc_id = aws_vpc.example.id
}

resource "aws_ecs_service" "example" {
  name = "example"
  cluster = aws_ecs_cluster.example.id
  task_definition = aws_ecs_task_definition.example.arn
  desired_count = 1

  depends_on = [
    aws_lb_listener.example,
    aws_alb_target_group.example
  ]

  network_configuration {
    subnets = aws_subnet.example_subnets.*.id
    security_groups = [
      aws_security_group.example_sg.id
    ]

    assign_public_ip = true
  }

  load_balancer {
    target_group_arn = aws_alb_target_group.example.arn
    container_name = "example-container"
    container_port = "80"
  }
}

这里创建了一个 load balancer、listener、target group 和 ECS 服务。在 ECS 服务中，load_balancer 块用于将服务注册到 ALB，而不是使用 terraform ecs with load_balancer 参数。