standby LB: device sync problem, after OS upgrade
After upgrading the OS of our two load balancers (from 12.1.5.2, to 13.1.3.4):
- The active load balancer did not experience any problem.
- The standby load balancer displayed the following behavior:
1. This error message is constantly displayed near the top of the GUI:
"This configuration has not yet loaded. If this message persists, it may indicate a configuration problem."
2. Its Network Map is empty.
(implying that all of the existing config, e.g. virtual servers, pools and nodes, before the OS upgrade, somehow disappeared)
3. In the Device Trust: Local Domain GUI page, this message is displayed:
"Recommended action: Synchronize <name of standby load balancer> to group device_trust_group"
Any suggestions on how to fix the problem in the standby load balancer would be greatly appreciated.