CircleCI machine image or resource class not valid

April 30, 2026 · View on GitHub

Playbook ID: circleci-resource-class-invalid Category: ci Severity: high Tags: circleci, resource-class, machine-image, executor, ci

What this failure means

A CircleCI job failed to start because the specified machine image or resource class is no longer valid, was removed, or was never available for the organization.

Common log signals

not a valid resource class
resource class.*is not a valid
machine image.*is not a valid
image.*not a valid resource class
Job was rejected
job failed to schedule
unsupported machine image
image was renamed

Diagnosis

CircleCI rejected the job at scheduling time because:

  • The machine image (e.g., ubuntu-2404:2026.02.2) was an internal or preview image that was removed from the index.
  • The resource class is not available for the specified executor or org plan.
  • The image name was renamed or deprecated between releases.

Fix steps

  1. Check the current list of available machine images on CircleCI Developer - Machine Images.

  2. Update the machine image to a stable, released version:

    machine:
  image: ubuntu-2404:2026.02.20

  3. For resource class errors, verify the class is available for your plan:

    resource_class: medium

  4. If using a preview or internal image, migrate to the stable alias:

    • ubuntu-2404:2026.02.2 → ubuntu-2404:2026.02.20
    • Or use docker-docker29 alias instead of direct image name.

  5. Contact CircleCI support if the error persists for stable images.

Validation

  • The pipeline triggers and the job is scheduled on the expected executor.
  • The job reaches the first step successfully.
  • No "not a valid resource class" or "image is not valid" error in the job setup.

Likely files to inspect

  • .circleci/config.yml

Run Faultline

faultline analyze build.log
faultline explain circleci-resource-class-invalid
faultline workflow build.log --json --mode agent

Search phrases this page answers

  • CircleCI machine image or resource class not valid
  • Ci: circleci machine image or resource class not valid
  • image.*not a valid resource class
  • GitHub Actions circleci machine image or resource class not valid
  • faultline explain circleci-resource-class-invalid

Generated from playbooks/bundled/log/ci/circleci-resource-class-invalid.yaml. Do not edit directly — run make docs-generate.