Client Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.4+k3s1", GitCommit:"8d0255af07e95b841952563253d27b0d10bd72f0", GitTreeState:"clean", BuildDate:"2023-04-20T00:33:18Z", GoVersion:"go1.19.8", Compiler:"gc", Platform:"linux/amd64"} Kustomize Version: v4.5.7 Server Version: version.Info{Major:"1", Minor:"26", GitVersion:"v1.26.4+k3s1", GitCommit:"8d0255af07e95b841952563253d27b0d10bd72f0", GitTreeState:"clean", BuildDate:"2023-04-20T00:33:18Z", GoVersion:"go1.19.8", Compiler:"gc", Platform:"linux/amd64"} master@master01:~$ ^C master@master01:~$ helm install rancher rancher-stable/rancher --namespace cattle-system --set hostname=172.16.26.7.sslip.io WARNING: Kubernetes configuration file is group-readable. This is insecure. Location: /home/master/.kube/config WARNING: Kubernetes configuration file is world-readable. This is insecure. Location: /home/master/.kube/config Error: INSTALLATION FAILED: chart requires kubeVersion: < 1.26.0-0 which is incompatible with Kubernetes v1.26.4+k3s1

Perhaps review support matrix: https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/rancher-v2-6-7/ I do not see Kubernetes version 1.26 (or perhaps my Tea hasn't kicked in yet)

You need to use a version of K3s that is compatible with Rancher. for now that is a 1.25 release.