Kubernetes cluster upgrade

Hi Team ,

When im going to upgrade a master cluster , its giving a fatal error , which has been attached below , please let me know why im getting that error

try it again with the following steps
To upgrade the master node, run

kubectl drain master --ignore-daemonsets
apt install kubeadm=1.18.0-00
kubeadm upgrade apply v1.18.0
apt install kubelet=1.18.0-00
kubectl uncordon master

To upgrade the worker nodes, run

kubectl drain node01 --ignore-daemonsets
ssh node01
node01$ apt install kubeadm=1.18.0-00
node01$ apt install kubelet=1.18.0-00
master$ kubeadm upgrade node config 
master$ kubectl uncordon node01

if the current version is 1.16, you should upgrade it v1.17 first then move to v1.18