ISSUE
The following error is displayed: The REST APIs are not supported on this appliance OS version
RESOLUTION
In order to use the updated user interface in Unitrends 9.0 and above, the Unitrends appliance must be running CentOS6.
Please consult CentOS 6 Upgrade Status for details on the process for upgrading your appliance from CentOS5 to CentOS6.
CAUSE
Attempting to use the new 9.0 UI on an appliance running CentOS5.