According to the message there is (or was) a communication issue between this and the other hosts. It looks like HA on this host could not recover from this issue by itself. Assuming the issue does not exist anymore, you may try to right click the host and run "Reconfigure for HA".
André
Hi
Welcome to the communities.
If it was working earlier please check if done any changes on network configuration .
If new must be gateway setting problem due to which its not communicating .