The message 'attach failed 4(not found), trying subscribe.' indicates the probe failed to create and attach to its queue.
Resolution
To help ensure the probe always connects to its queue a permanent queue can be created. Open the hub configure GUI Queues tab > New Name = snmpgtw Type = attach Subject = alarm
It is recommended to use the latest robot and hub updates.
Additional Information
By default the snmpgtw probe will create a temp queue each time it is activated. The queue name will be t_<next available number>.
If a queue is created with the name snmpgtw, the probe will use that rather than creating a temp queue.