I got this error in a new deployment of Veeam Backup & Replication 9.5 Update 4. The error occured every day at 9 pm.
24.02.2019 21:00:11 :: Error: Remote deployment and management is available for licensed agents only. Please change your backup server settings to allow managed agents to consume the license, then perform a protection group rescan.
The solution to this issue is pretty simple. Make sure that you allow the consumption of licenses for free agents. You will find this option under General > License.
Another workaround is to disable the protection group. Right click “Manually Added” under “Physical & Cloud Infrastructure” and click “Disable”.
Let me know if one of these workarounds worked for you. :)