We're getting warning message as mentioned below, while running backup using bitbucket-backup-client.
"WARN The current version of the restore client (3.3.3) lacks the necessary features to restore backups for Bitbucket 6.10.4. Backups will be performed successfully, but you must upgrade the restore client in order to restore them. To fail in this situation, please change the backup.requirerestorable property in backup-config.properties"
So, I've downloaded the latest version of restore client .zip file from https://marketplace.atlassian.com/apps/1211500/bitbucket-server-backup-client/ (which supports our bitbucket server version). After extracting the downloaded .zip file, I've used restore-client.jar file alone. Replaced the old restore-client.jar file with this new one with required file permission and restarted bitbucket service.
Even after the above procedure, am still getting WARN message that am still using restore client (3.3.3). (- When running the backup again)
NOTE: I've not used latest backupclient.jar since it's running without issue. I've just replaced old restore-client.jar with new one.