NullPointerException in principalServer
When you launch several samarah, sometime you have the following exception: ` 2023-11-16 13:52:15.856 ERROR 834100 --- [SocketWorker-31] c.s.P.module.fodomust.FodoMustServer : java.lang.NullPointerException: Cannot invoke "jcl.learning.classifications.Classification.getData()" because "classif" is null
java.lang.NullPointerException: Cannot invoke "jcl.learning.classifications.Classification.getData()" because "classif" is null at managers.ClassificationManager.getRootClassif(ClassificationManager.java:1060) ~[classes/:na] at com.sdc_icube.PrincipalServer.module.fodomust.FodoMustServer.onMessage(FodoMustServer.java:414) ~[classes/:na] at org.java_websocket.server.WebSocketServer.onWebsocketMessage(WebSocketServer.java:712) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.drafts.Draft_6455.processFrameText(Draft_6455.java:986) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.drafts.Draft_6455.processFrame(Draft_6455.java:910) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.WebSocketImpl.decodeFrames(WebSocketImpl.java:401) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.WebSocketImpl.decode(WebSocketImpl.java:233) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.server.WebSocketServer$WebSocketWorker.doDecode(WebSocketServer.java:1114) ~[Java-WebSocket-1.5.3.jar:na] at org.java_websocket.server.WebSocketServer$WebSocketWorker.run(WebSocketServer.java:1086) ~[Java-WebSocket-1.5.3.jar:na] `