No log da aplicação fica dando esse erro.
java.lang.IllegalStateException: Calling [asyncError()] is not valid for a request with Async state [MUST_DISPATCH]
at org.apache.coyote.AsyncStateMachine.asyncError(AsyncStateMachine.java:440) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.coyote.AbstractProcessor.action(AbstractProcessor.java:512) [tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.coyote.Request.action(Request.java:430) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.catalina.core.AsyncContextImpl.setErrorState(AsyncContextImpl.java:401) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.catalina.connector.CoyoteAdapter.asyncDispatch(CoyoteAdapter.java:239) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.coyote.AbstractProcessor.dispatch(AbstractProcessor.java:241) [tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:53) [tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834) [tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415) [tomcat-embed-core-9.0.17.jar:9.0.17]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.17.jar:9.0.17]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_211]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_211]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.17.jar:9.0.17]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_211]
