Helm "failed to download chart" from a repository in CI

Helm fetches a chart from a repo or OCI registry before rendering. If the repo index is stale, the version does not exist, or the registry is unreachable, the download fails before any templating.

What this error means

A helm upgrade/install or helm pull step fails to download the chart, reporting the chart/version is not found in the repository or that the repo could not be reached.

helm

Error: failed to download "bitnami/redis" at version "18.6.1"

# or, repo not added/updated:
Error: chart "redis" version "18.6.1" not found in
https://charts.bitnami.com/bitnami repository

Common causes

Repo not added or index stale

CI never ran helm repo add/helm repo update, so the index lacks the chart/version.

Version does not exist

The pinned chart version was removed or mistyped.

Registry unreachable

A network/proxy block or transient outage prevents the download.

How to fix it

Add and update the repo, then pin a valid version

Terminal

helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update
helm search repo bitnami/redis --versions | head

Confirm reachability and version

Verify the exact chart version exists in helm search repo.
Allow egress to the chart repo / OCI registry through any proxy.
Retry a transient download failure.

How to prevent it

Run helm repo add/helm repo update (or helm registry login for OCI) before deploy.
Pin chart versions that you have verified exist.
Vendor critical charts internally for air-gapped CI.