Output of helm version:
version.BuildInfo{Version:"v3.0.1", GitCommit:"7c22ef9ce89e0ebeb7125ba2ebf7d421f3e82ffa", GitTreeState:"clean", GoVersion:"go1.13.4"}

Output of kubectl version:
Client Version: version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.1", GitCommit:"eec55b9ba98609a46fee712359c7b5b365bdd920", GitTreeState:"clean", BuildDate:"2018-12-13T10:39:04Z", GoVersion:"go1.11.2", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"13", GitVersion:"v1.13.1", GitCommit:"eec55b9ba98609a46fee712359c7b5b365bdd920", GitTreeState:"clean", BuildDate:"2018-12-13T10:31:33Z", GoVersion:"go1.11.2", Compiler:"gc", Platform:"linux/amd64"}

Cloud Provider/Platform (AKS, GKE, Minikube etc.):
Minikube

I'm trying to helm install but helm comes back saying with following error
Error: rendered manifests contain a resource that already exists. Unable to continue with install: existing resource conflict: kind: CustomResourceDefinition, namespace: , name: scheduledsparkapplications.sparkoperator.k8s.io

but when I do helm list --all, nothing comes up and therefore I unable to remove any resource to proceed with installation.

Any help appreciated! Thanks!

See the attached screenshot: