Totally understand the confusion—seeing “Not ready” when you have a worker running is frustrating. In Prefect 3.x, a deployment shows Not ready when the server thinks there are no compatible, online workers able to pick it up. That can be a real configuration issue, or (in some older versions) just a stale UI status. Quick checks to run - Verify the deployment’s target pool/queue

prefect deployment inspect "your-flow/your-deployment"

Confirm the

work_pool_name

(and

work_queue_name

if set). - Verify the pool is healthy and workers are online

prefect work-pool inspect "your-pool"

Look for: - Pool not paused - Concurrency limit not zero or exhausted - At least one online worker connected to this pool - Verify queues

prefect work-queue ls

If your worker was started with

--work-queue

, confirm the names match exactly and queues are not paused and have non-zero concurrency limits. - Confirm worker startup args match the deployment - If your deployment targets the pool only:

prefect worker start -p "your-pool"

- If your deployment targets a specific queue:

prefect worker start -p "your-pool" -q "your-queue"

Make sure you didn’t start the worker on a different pool or queue than the deployment expects. Common causes of “Not ready” - The worker is polling a different pool or queue than the deployment. - The pool or queue is paused, or has a zero/exhausted concurrency limit. - Pool type and job variables don’t match the worker environment (e.g., a Docker/K8s-style job template under a process worker pool). - The worker is offline or has not heartbeated recently. - Older Prefect versions had a UI/server bug where deployments stayed Not ready even with a running worker. This was fixed—upgrading usually resolves it: - Issue: Confusing deployment status in the UI - Fix: Fix stale deployment statuses If everything above looks correct but the UI still says Not ready, try: - Restarting the worker process (to force a fresh heartbeat) - Pausing/resuming the work pool in the UI (to force a refresh) - Upgrading to the latest Prefect 3.x on both worker and server/UI Could you share a bit more so I can pinpoint it? - Are you on Prefect Cloud or self-hosted? - Output of:

prefect version

- The result of:

prefect deployment inspect "your-flow/your-deployment"
  prefect work-pool inspect "your-pool"

- Did you start the worker with any

--work-queue

arguments? - On the deployment page, do you see any readiness messages or hints about why it’s Not ready? A screenshot or the text would help. Once we have those, we can zero in on the exact cause quickly.