cf tasks throws 500 response code

Products

• VMware Tanzu Application Service

Issue/Introduction

Concourse pipeline deploys an app and the pipeline also check for tasks status

cf tasks <app-name>

but it fails with

Detail: {"errors":[{"title":"UnknownError","detail":"An unknown error occurred.","code":10001}]}

Checking into the cloud controller logs to get more info it shows:

cloud_controller.####.2025-08-14-00-34-15.tgz/cloud_controller_ng/cloud_controller_ng.log.7:{"timestamp":"2025-08-12T22:58:26.793785264Z","message":"Request failed: 500: {\"errors\"=\u003e[{\"title\"=\u003e\"UnknownError\", \"detail\"=\u003e\"An unknown error occurred.\", \"code\"=\u003e10001, \"test_mode_info\"=\u003e{\"detail\"=\u003e\"docker? delegated to droplet, but droplet is nil\", \"title\"=\u003e\"CF-\", \"backtrace\"=\u003e[\"/var/vcap/data/packages/cloud_controller_ng/4fdf44ff279cc5b4cb790a4208bb5402e5e8b078/cloud_controller_ng/app/models/runtime/task_model.rb:59:in `rescue in docker?'\", 

Cause

The error droplet is nil indicate that the app deployment was not completed so when you are check cf tasks <app-name> this give you 500 response code.

Resolution

To resolve this make sure your app was completely deployed, you can check by using

cf app <app-name>

cf logs <app-name> --recent

before running

cf tasks <app-name>