This restriction no longer applies once the appliance has been upgraded to a new firmware.
ACC Remote Site Upgrade feature must be used. Due to the size of the upgrade package, upgrading to this release via WebUI from firmwares prior to 1.4.8.50 is not supported. Version 3.4.24.16 (ACC Version 6.14.4.6) Released Release Summary This is a service release that includes several bug fixes and performance improvements for ES Appliances.
Avigilon Control Center™ ES Analytics Appliance and ES HD Recorder Release Notes