I try to specify savepoint dir in my app. However, the startup task reports an error, java.lang.unsupported operationexception: the configuration is unmodifiable; its contents cannot be changed.

String savepointDir;
if (Strings.isNotBlank(savepointDir = parameterTool.get("system.savepoint.dir"))) {
    env.setDefaultSavepointDirectory(savepointDir);
}

2021-07-27 16:26:34.029 [travel_spilt -> (Sink: sink_es_insert, Sink: sink_es_update) (1/1)#31] WARN  org.apache.flink.runtime.taskmanager.Task  - travel_spilt -> (Sink: sink_es_insert, Sink: sink_es_update) (1/1)#31 (1f33925046e04307ba6beb3959d2cad5) switched from DEPLOYING to FAILED with failure cause: java.lang.UnsupportedOperationException: The configuration is unmodifiable; its contents cannot be changed.2021-07-27 16:26:34.029 [travel_spilt -> (Sink: sink_es_insert, Sink: sink_es_update) (1/1)#31] WARN  org.apache.flink.runtime.taskmanager.Task  - travel_spilt -> (Sink: sink_es_insert, Sink: sink_es_update) (1/1)#31 (1f33925046e04307ba6beb3959d2cad5) switched from DEPLOYING to FAILED with failure cause: java.lang.UnsupportedOperationException: The configuration is unmodifiable; its contents cannot be changed. at org.apache.flink.configuration.UnmodifiableConfiguration.error(UnmodifiableConfiguration.java:73) at org.apache.flink.configuration.UnmodifiableConfiguration.setValueInternal(UnmodifiableConfiguration.java:63) at org.apache.flink.configuration.Configuration.set(Configuration.java:709) at org.apache.flink.runtime.state.CheckpointStorageLoader.load(CheckpointStorageLoader.java:174) at org.apache.flink.streaming.runtime.tasks.StreamTask.createCheckpointStorage(StreamTask.java:1231) at org.apache.flink.streaming.runtime.tasks.StreamTask.<init>(StreamTask.java:337) at org.apache.flink.streaming.runtime.tasks.StreamTask.<init>(StreamTask.java:308) at org.apache.flink.streaming.runtime.tasks.StreamTask.<init>(StreamTask.java:281) at org.apache.flink.streaming.runtime.tasks.StreamTask.<init>(StreamTask.java:273) at org.apache.flink.streaming.runtime.tasks.StreamTask.<init>(StreamTask.java:263) at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.<init>(OneInputStreamTask.java:65) at sun.reflect.GeneratedConstructorAccessor339.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.apache.flink.runtime.taskmanager.Task.loadAndInstantiateInvokable(Task.java:1524) at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:730) at org.apache.flink.runtime.taskmanager.Task.run(Task.java:566) at java.lang.Thread.run(Thread.java:748)