NPE on empty File Input in Embedded Form

15:34:17,999 ERROR [io.undertow.request] (default task-115) UT005023: Exception handling request to /camunda/api/engine/engine/default/process-definition/RequestToOfferProcess:6:3ea6a0a5-9300-11e7-b4f6-faa5f58a479f/submit-form: java.lang.RuntimeException: org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
	at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter$1.execute(AuthenticationFilter.java:61)
	at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter$1.execute(AuthenticationFilter.java:56)
	at org.camunda.bpm.webapp.impl.security.SecurityActions.runWithAuthentications(SecurityActions.java:38)
	at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter.doFilter(AuthenticationFilter.java:56)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
	at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
	at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
	at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
	at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
	at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
	at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
	at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
	at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
	at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
	at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:292)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$100(ServletInitialHandler.java:81)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:138)
	at io.undertow.servlet.handlers.ServletInitialHandler$2.call(ServletInitialHandler.java:135)
	at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:48)
	at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43)
	at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
	at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
	at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
	at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
	at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44)
	at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
	at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
	at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
	at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
	at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:805)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.jboss.resteasy.spi.UnhandledException: java.lang.NullPointerException
	at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:77)
	at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:220)
	at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:175)
	at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:418)
	at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:209)
	at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221)
	at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
	at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
	at org.camunda.bpm.engine.rest.filter.CacheControlFilter.doFilter(CacheControlFilter.java:41)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.camunda.bpm.engine.rest.filter.EmptyBodyFilter.doFilter(EmptyBodyFilter.java:95)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.camunda.bpm.webapp.impl.security.filter.SecurityFilter.doFilterSecure(SecurityFilter.java:67)
	at org.camunda.bpm.webapp.impl.security.filter.SecurityFilter.doFilter(SecurityFilter.java:51)
	at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
	at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
	at org.camunda.bpm.webapp.impl.security.auth.AuthenticationFilter$1.execute(AuthenticationFilter.java:59)
	... 42 more
Caused by: java.lang.NullPointerException
	at org.camunda.bpm.engine.variable.impl.type.FileValueTypeImpl.createValue(FileValueTypeImpl.java:44)
	at org.camunda.bpm.engine.rest.dto.VariableValueDto.toTypedValue(VariableValueDto.java:123)
	at org.camunda.bpm.engine.rest.dto.VariableValueDto.toMap(VariableValueDto.java:146)
	at org.camunda.bpm.engine.rest.sub.repository.impl.ProcessDefinitionResourceImpl.submitForm(ProcessDefinitionResourceImpl.java:177)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139)
	at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295)
	at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249)
	at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:138)
	at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:107)
	at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:133)
	at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:101)
	at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:402)
	... 60 more