The RLM module may become unresponsive and you may see the following messages in the Syslog:
You can resolve the issue by rebooting the RLM from the CLI.
Log on using the CLI (SSH or console), then reboot the RLM.
CLI: rlm reboot
Wait for a while and verify the RLM is back online:
CLI: rlm status
The output of the command should report: Status: Online