Fix "zimbraRemoteManagementPrivateKeyPath (/opt/zimbra/.ssh/zimbra_identity) does not exist" on Zimbra Admin console

When using the Zimbra Admin console, clicking a menu to open its page may display an error window with this message:

“server zimbra.mail.ezymailhosting.com zimbraRemoteManagementPrivateKeyPath (/opt/zimbra/.ssh/zimbra_identity) does not exist”

This problem is caused by missing SSH keys. To resolve it, generate new SSH keys by running:

zmsshkeygen
zmupdateauthkeys

For a multi-server system, run the following command on every server:

zmupdateauthkeys