[SOLVED] Spring loaded stacktrace

IIUC spring-loaded enables me change java server code without redeploying and it works, but I got a ridiculously long stacktrace. What does it mean?

18:53:09: Executing external task 'bootRun'...
:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:findMainClass
:bootRun

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.3.5.RELEASE)

2016-07-15 18:53:13.710  INFO 9337 --- [           main] hello.Application                        : Starting Application on dac-Latitude-E7450 with PID 9337 (/home/dac/Downloads/initial/build/classes/main started by dac in /home/dac/Downloads/initial)
2016-07-15 18:53:13.714  INFO 9337 --- [           main] hello.Application                        : No active profile set, falling back to default profiles: default
2016-07-15 18:53:13.811  INFO 9337 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@221af3c0: startup date [Fri Jul 15 18:53:13 CEST 2016]; root of context hierarchy
2016-07-15 18:53:13.986 ERROR 9337 --- [           main] org.springsource.loaded.jvm.JVM          : Problems copying method. Incompatible JVM?

java.lang.reflect.InvocationTargetException: null
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
    at org.springsource.loaded.jvm.JVM.copyMethod(JVM.java:134) ~[springloaded-1.2.1.RELEASE.jar:1.2.1.RELEASE]
    at org.springsource.loaded.ri.OriginalClassInvoker.createJavaMethod(OriginalClassInvoker.java:68) [springloaded-1.2.1.RELEASE.jar:1.2.1.RELEASE]
    at org.springsource.loaded.ri.ReflectiveInterceptor.jlClassGetDeclaredMethods(ReflectiveInterceptor.java:151) [springloaded-1.2.1.RELEASE.jar:1.2.1.RELEASE]
    at org.springframework.core.type.StandardAnnotationMetadata.getAnnotatedMethods(StandardAnnotationMetadata.java:152) [spring-core-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:292) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:232) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:199) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:168) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:321) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:243) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:273) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:98) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:678) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:520) [spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE]
    at hello.Application.main(Application.java:13) [main/:na]
Caused by: java.lang.IllegalArgumentException: Can not copy a non-root Method
    at java.lang.reflect.Method.copy(Method.java:151) ~[na:1.8.0_91]
    ... 25 common frames omitted

2016-07-15 18:53:15.426 ERROR 9337 --- [           main] org.springsource.loaded.jvm.JVM          : Problems copying method. Incompatible JVM?

Mu build.gradle

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.5.RELEASE")
        classpath("org.springframework:springloaded:1.2.1.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'
apply plugin: 'rebel'

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath group: 'org.zeroturnaround', name: 'gradle-jrebel-plugin', version: '1.1.3'
    }
}
jar {
    baseName = 'gs-spring-boot'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
    // tag::jetty[]
    compile("org.springframework.boot:spring-boot-starter-web") {
        exclude module: "spring-boot-starter-tomcat"
    }
    compile("org.springframework.boot:spring-boot-starter-jetty")
    // end::jetty[]
    // tag::actuator[]
    compile("org.springframework.boot:spring-boot-starter-actuator")
    // end::actuator[]
    compile("org.springframework.boot:spring-boot-starter-actuator")
    testCompile("org.springframework.boot:spring-boot-starter-test")
    testCompile("junit:junit")

}

// change default IntelliJ output directory for compiling classes
idea {
    module {
        inheritOutputDirs = false
        outputDir = file("$buildDir/classes/main/")
    }
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.3'
}

My class that I can reload without restarting jetty

package hello;

import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.RequestMapping;

@RestController
public class HelloController {

    @RequestMapping("/")
    public String index() {
        return "Greetings from Spring Boot!";
    }

}

But why do I get the stacktrace and how do I fix it?