Monitoring, Management & Location Tracking

What does the below error message in event logs in Airwave mean?

Device Monitor (Poll Now): Can't locate object method "needs_fw_build_update" via package "Mercury::Device::Universal::Cust

When we add a new device in Airwave, Airwave uses the OID "sysDescr" to poll the basic details for the device such as Name, Device model, Firmware version etc. So, in scenarios where the particular devices are not supported in Airwave and since Airwave is not able to fetch the firmware information for this device, Airwave indicates us using this particular error messages in Event viewer log.