A "quick" fix is probably to update Helm to a newer version and / or removing Helm 2.
[...]
Adding stable repo with URL: kubernetes-charts.storage.googleapis.com
Error: error initializing: Looks like "kubernetes-charts.storage.googleapis.com" is not a valid chart repository or cannot be reached: Failed to fetch kubernetes-charts.storage.googleapis.com/index.yaml : 403 Forbidden
[...]