There's a kubernetes cluster that was created by kops and when running kops validate this is the output:
    INSTANCE GROUPS
NAME            ROLE    MACHINETYPE MIN MAX SUBNETS
master-us-east-1a   Master  m4.xlarge   1   1   us-east-1a
nodes           Node    c4.2xlarge  1   75  us-east-1a
NODE STATUS
NAME                ROLE    READY
ip-172-20-59-93.ec2.internal    master  False
VALIDATION ERRORS
KIND    NAME                MESSAGE
Machine i-0a44bbdd18c86e846     machine "i-0a44bbdd18c86e846" has not yet joined cluster
Machine i-0d3302056f3dfeef0     machine "i-0d3302056f3dfeef0" has not yet joined cluster
Machine i-0d6199876b91962f4     machine "i-0d6199876b91962f4" has not yet joined cluster
Node    ip-172-20-59-93.ec2.internal    master "ip-172-20-59-93.ec2.internal" is not ready
Validation Failed
How I can recover this cluster?