io.openvidu.client.OpenViduException: No connection found for participant with privateId

My servers setting is

Openvidu version: 2.14
media-server:6.13.2
CERTIFICATE_TYPE=owncert
OPENVIDU_PRO_CLUSTER_MODE=manual
OPENVIDU_PRO_CLUSTER_ENVIRONMENT=on_premise
OPENVIDU_PRO_CLUSTER_LOAD_STRATEGY=streams

i got the error message after openvidu restarted.
but the service is ok.
I wonder if I don’t have to mind this kind of error message or what to do?

openvidu-server_1 | ____ __ ___ _
openvidu-server_1 | / __ \ \ \ / () | |
openvidu-server_1 | | | | |
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openvidu-server_1 | | | | | ’
\ / _ \ ’
\ / / | |/ ` | | | | | _ _ _ ___
openvidu-server_1 | | |__| | |
) | / | | \ / | | (| | || | | / '/ _
openvidu-server_1 | _
/| ./ _|| ||/ ||_,|_,| || || __/
openvidu-server_1 | | |
openvidu-server_1 | |
| version 2.14.0
openvidu-server_1 | ______________________________________________________________
openvidu-server_1 |
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,906 [rbeatExec-e1-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Error sending heartbeat to server. Exception: [KurentoClient] Interrupted while waiting for a response
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,921 [rbeatExec-e1-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Stopping heartbeat and closing client: failure during heartbeat mechanism
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,928 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcErrorException:‘params’ is requiered. Code: -32602. Data: {“type”:“INVALID_PARAMS”}
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,956 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcClientClosedException:Trying to send a message in a client closed explicitly. When a client is closed, it can’t be reused. It is necessary to create another one
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,957 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with channel == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,957 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with group == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,968 [rbeatExec-e2-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Error sending heartbeat to server. Exception: [KurentoClient] Interrupted while waiting for a response
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,969 [rbeatExec-e2-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Stopping heartbeat and closing client: failure during heartbeat mechanism
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,969 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcErrorException:‘params’ is requiered. Code: -32602. Data: {“type”:“INVALID_PARAMS”}
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,970 [ntLoopGroup-3-1] org.kurento.jsonrpc.internal.ws.PendingRequests - Received response {“id”:1,“result”:{“value”:“pong”},“jsonrpc”:“2.0”} with an id not registered as pending request. Maybe the request timed out
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,985 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcClientClosedException:Trying to send a message in a client closed explicitly. When a client is closed, it can’t be reused. It is necessary to create another one
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,985 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with channel == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:23,985 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with group == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,005 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcErrorException:‘params’ is requiered. Code: -32602. Data: {“type”:“INVALID_PARAMS”}
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,006 [rbeatExec-e3-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Error sending heartbeat to server. Exception: InterruptedException while trying to acquire lock
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,006 [rbeatExec-e3-t0] org.kurento.jsonrpc.client.JsonRpcClient - [KurentoClient] Stopping heartbeat and closing client: failure during heartbeat mechanism
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,020 [main] org.kurento.jsonrpc.client.AbstractJsonRpcClientWebSocket - [KurentoClient] Exception sending close message. org.kurento.jsonrpc.JsonRpcClientClosedException:Trying to send a message in a client closed explicitly. When a client is closed, it can’t be reused. It is necessary to create another one
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,020 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with channel == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,020 [main] org.kurento.jsonrpc.client.JsonRpcClientNettyWebSocket - [KurentoClient] Trying to close a JsonRpcClientNettyWebSocket with group == null
openvidu-server_1 | [WARN] 2020-08-10 06:47:24,021 [main] io.openvidu.server.pro.OpenViduServerPro - You have set property server.port (or SERVER_PORT). This will serve OpenVidu Server Pro on your host at port 5443. But property HTTPS_PORT (443) still configures the port that should be used to connect to OpenVidu Server from outside. Bear this in mind when configuring a proxy in front of OpenVidu Server
openvidu-server_1 | [WARN] 2020-08-10 06:47:25,524 [main] io.openvidu.server.pro.OpenViduServerPro - OpenVidu Pro cluster mode is ‘manual’. There will be no automatic instances management
openvidu-server_1 | [ERROR] 2020-08-10 06:47:27,329 [main] io.openvidu.server.coturn.CoturnCredentialsService - COTURN DB is not empty
openvidu-server_1 | [WARN] 2020-08-10 06:56:28,514 [0.0-5443-exec-7] org.kurento.jsonrpc.internal.server.PingWatchdogManager - Received first ping request without ‘interval’
openvidu-server_1 | [ERROR] 2020-08-10 06:56:28,514 [0.0-5443-exec-7] org.kurento.jsonrpc.internal.ws.JsonRpcWebSocketHandler - Trying to send a message to a closed session
openvidu-server_1 | [WARN] 2020-08-10 06:56:28,515 [eo7elrdb-e37-t0] io.openvidu.server.rpc.RpcHandler - No connection found for participant with privateId 4dvmlfq6ukf4ek4apmeo7elrdb when trying to execute method ‘sendMessage’. Method ‘Session.connect()’ must be the first operation called in any session
openvidu-server_1 | [ERROR] 2020-08-10 06:56:28,517 [eo7elrdb-e37-t0] org.kurento.jsonrpc.internal.JsonRpcHandlerManager - Exception while processing request {“id”:49,“method”:“sendMessage”,“params”:{“message”:"{“to”:[],“data”:"{\“type\”:\“textbook_page_confirm\”,\“confUuid\”:\“1049f407268b8831d8d469d734d0029298edd25726e2c8\”,\“imageSaveKey\”:\“1049f407268b8831d8d469d734d0029298edd25726e2c8:W1/writing/B:31\”,\“pagePath\”:31}",“type”:“signal:textbook_page_confirm”}"},“jsonrpc”:“2.0”}
openvidu-server_1 | io.openvidu.client.OpenViduException: No connection found for participant with privateId 4dvmlfq6ukf4ek4apmeo7elrdb. Method ‘Session.connect()’ must be the first operation called in any session. Code: 803
openvidu-server_1 | at io.openvidu.server.rpc.RpcHandler.handleRequest(RpcHandler.java:98)
openvidu-server_1 | at org.kurento.jsonrpc.internal.JsonRpcHandlerManager.handleRequest(JsonRpcHandlerManager.java:142)
openvidu-server_1 | at org.kurento.jsonrpc.internal.server.ProtocolManager$3.run(ProtocolManager.java:218)
openvidu-server_1 | at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
openvidu-server_1 | at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
openvidu-server_1 | at java.lang.Thread.run(Thread.java:748)
openvidu-server_1 | [ERROR] 2020-08-10 06:56:28,517 [eo7elrdb-e37-t0] org.kurento.jsonrpc.internal.ws.JsonRpcWebSocketHandler - Trying to send a message to a closed session

Please update to latest version (2.15 in this moment).