Ошибка при запуске нового экземпляра процесса

У меня есть процесс bpmn под названием "vacaciones". Я правильно запускаю внутри кода Java следующим образом (это работает):

runtimeService.startProcessInstanceByKey ("vacaciones");

Но при использовании Camunda Rest api та же операция не выполняется. Я делаю следующий запрос POST:

POST URL-метода http://localhost:7002/rest/engine/default/process-definition/key/vacaciones/start

Заголовки Content-Type: application / json

И я получаю такой ответ с ошибкой:

GRAVE: Servlet.service() para servlet default lanzó excepción
org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
    at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:76)
    at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:212)
    at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:149)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:372)
    at org.jboss.resteasy.core.SynchronousDispatcher.invokePropagateNotFound(SynchronousDispatcher.java:217)
    at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:224)
    at org.jboss.resteasy.plugins.server.servlet.FilterDispatcher.doFilter(FilterDispatcher.java:62)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:41)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at org.camunda.bpm.engine.rest.sub.repository.impl.ProcessDefinitionResourceImpl.startProcessInstance(ProcessDefinitionResourceImpl.java:95)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:137)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:296)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:250)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:140)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:109)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:135)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:103)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:356)
    ... 23 more

Что случилось?