MQTT publish error - Tahu client internal error

I got this error some times. What should I do?
(What causes INTERNAL ERROR?)

[MQTT publish, exception] writeMoveFinalGoal
INFO   | jvm 1    | 2024/07/31 19:37:48 | I [c.c.m.e.g.EngineRPCImpl       ] [10:37:47]: Publishing client message on thirabots/SIDIZ_3/task/task_goal sfc-chart-id=9109511e-34fd-4fa9-b357-1a031578d124, sfc-chart-name=moveToCharger
INFO   | jvm 1    | 2024/07/31 19:37:48 | E [SFC Traffic move ext          ] [10:37:47]: Traceback (most recent call last):
INFO   | jvm 1    | 2024/07/31 19:37:48 |   File "<Script name="">", line 7, in onStart
INFO   | jvm 1    | 2024/07/31 19:37:48 |   File "<module:sfc.traffic_move.moveToGoal>", line 98, in onStart
INFO   | jvm 1    | 2024/07/31 19:37:48 |   File "<module:robot.mqtt>", line 272, in sendGoalNode
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at org.eclipse.tahu.mqtt.TahuClient.publish(TahuClient.java:460)
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at com.cirruslink.mqtt.engine.gateway.EngineRPCImpl.publishImpl(EngineRPCImpl.java:60)
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at com.cirruslink.mqtt.engine.common.EngineAbstractScriptModule.publish(EngineAbstractScriptModule.java:30)
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at jdk.internal.reflect.GeneratedMethodAccessor27.invoke(Unknown Source)
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
INFO   | jvm 1    | 2024/07/31 19:37:48 | 	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
INFO   | jvm 1    | 2024/07/31 19:37:48 | org.eclipse.tahu.exception.TahuException: org.eclipse.tahu.exception.TahuException: INTERNAL_ERROR
INFO   | jvm 1    | 2024/07/31 19:37:48 |  sfc-chart-id=9109511e-34fd-4fa9-b357-1a031578d124, sfc-chart-name=moveToCharger
INFO   | jvm 1    | 2024/07/31 19:37:48 | W [c.i.s.ChartInstance           ] [10:37:47]: Chart 'moveToCharger' aborted in 'Script[Step:moveToCharge]' sfc-chart-id=9109511e-34fd-4fa9-b357-1a031578d124, sfc-chart-name=moveToCharger