Experion ERDB Failed

We have 4 redundant Experion Servers in our petrochemical complex. In one of the redundant systems, ERDB status is highlighted as FAILED in Server redundancy page (sys113.dsp). Also there is a SYNC ERROR highlighted in red in control builder. Server redundancy is working fine. Clients are switching over without any problem in case of server switch over. What are the risks of running the server in ERDB failed state? I have already formatted and reinstalled the server application on both machines but the issue persists.

Please suggest a solution.