Problem description

Only seen this in airsonic.log
`2020-03-09 19:34:00.189 ERROR --- o.s.w.s.s.s.DefaultHandshakeHandler : Handshake failed due to invalid Upgrade header: null
2020-03-09 19:34:06.026 ERROR --- o.a.p.s.LoggingExceptionResolver : 127.0.0.1: An exception occurred while loading http://music.cloud-dorel.ml/websocket/718/mcvcgorq/xhr_streaming?t=

org.springframework.http.converter.HttpMessageNotWritableException: No converter for [class java.util.LinkedHashMap] with preset Content-Type 'application/javascript;charset=UTF-8'
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:309) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:226) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82) ~[spring-web-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:124) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:523) ~[jakarta.servlet-api-4.0.3.jar!/:4.0.3]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.4.RELEASE.jar!/:5.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:590) ~[jakarta.servlet-api-4.0.3.jar!/:4.0.3]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:580) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:516) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:388) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:253) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:348) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.core.AsyncContextImpl.setErrorState(AsyncContextImpl.java:449) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.catalina.connector.CoyoteAdapter.asyncDispatch(CoyoteAdapter.java:176) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.coyote.AbstractProcessor.dispatch(AbstractProcessor.java:237) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:59) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.31.jar!/:9.0.31]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
`

Steps to reproduce

Don't know

System information

Airsonic version: 10.6.0-SNAPSHOT.20200302045745**

Operating system: *Debian 10.

Java version: java 11.0.5.

Proxy server: *NGINX

Client: Chrome.

Language: French