ntopng failed to start after upgraded to 21.1.5

[nicholaswc]

I just upgraded my firewall from 19.x to 21.1.5. The ntopng service can't be started now. I have tried to reinstalled redis and ntopng services. Deleted ntopng and redis folders before reinstall servcies. Here is the log records when I restarts the ntopng service:
Date                                 Process             Line
2021-05-24T14:25:59   root[54924]   /usr/local/etc/rc.d/ntopng: WARNING: failed to start ntopng   
2021-05-24T14:25:59   ntopng[92432]   [Redis.cpp:150] ERROR: to specify a redis server other than the default   
2021-05-24T14:25:59   ntopng[92432]   [Redis.cpp:149] ERROR: Please start it and try again or use -r   
2021-05-24T14:25:59   ntopng[92432]   [Redis.cpp:148] ERROR: ntopng requires redis server to be up and running   
2021-05-24T14:25:58   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:55   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:53   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:50   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:48   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:45   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:43   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:40   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:38   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:35   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:32   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:30   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:27   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:25   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:22   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]   
2021-05-24T14:25:20   ntopng[92432]   [Redis.cpp:99] ERROR: Connection error [Operation timed out]

[mimugmail]

Go to Redis and reset the DB, then check if the service is running

[nicholaswc]

Thanks for your reply. I reinstall the redis and ntopng service and restarts the firewall. It works.