Asana importer throws "NullPointerException: name argument cannot be null" during import process

2016-03-24 14:22:29,811 INFO - Import started by admin using com.atlassian.jira.plugins.importer.asana.AsanaDataBean
2016-03-24 14:22:31,009 INFO - ------------------------------
2016-03-24 14:22:31,010 INFO - Importing: Users
2016-03-24 14:22:31,010 INFO - ------------------------------
2016-03-24 14:22:31,010 INFO - Only new items will be imported
2016-03-24 14:22:45,818 ERROR - Unexpected failure occurred. Importer will stop immediately. Data may be in an unstable state
java.lang.NullPointerException: name argument cannot be null
	at org.apache.commons.lang3.Validate.notNull(Validate.java:222)
	at com.atlassian.crowd.directory.AbstractInternalDirectory.findUserByName(AbstractInternalDirectory.java:171)
	at com.atlassian.crowd.directory.DbCachingRemoteDirectory.findUserByName(DbCachingRemoteDirectory.java:179)
	at com.atlassian.crowd.manager.directory.DirectoryManagerGeneric.findUserByName(DirectoryManagerGeneric.java:289)
	at com.atlassian.crowd.manager.application.ApplicationServiceGeneric.findUserByName(ApplicationServiceGeneric.java:344)
	at com.atlassian.crowd.embedded.core.CrowdServiceImpl.getUser(CrowdServiceImpl.java:94)
	at com.atlassian.crowd.embedded.core.DelegatingCrowdService.getUser(DelegatingCrowdService.java:43)
	at com.atlassian.crowd.embedded.core.FilteredCrowdServiceImpl.getUser(FilteredCrowdServiceImpl.java:51)
	at sun.reflect.GeneratedMethodAccessor821.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at com.atlassian.plugin.util.ContextClassLoaderSettingInvocationHandler.invoke(ContextClassLoaderSettingInvocationHandler.java:26)
	at com.sun.proxy.$Proxy106.getUser(Unknown Source)
	at sun.reflect.GeneratedMethodAccessor821.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
	at org.eclipse.gemini.blueprint.service.importer.support.internal.aop.ServiceInvoker.doInvoke(ServiceInvoker.java:56)
	at org.eclipse.gemini.blueprint.service.importer.support.internal.aop.ServiceInvoker.invoke(ServiceInvoker.java:60)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:133)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:121)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.eclipse.gemini.blueprint.service.util.internal.aop.ServiceTCCLInterceptor.invokeUnprivileged(ServiceTCCLInterceptor.java:70)
	at org.eclipse.gemini.blueprint.service.util.internal.aop.ServiceTCCLInterceptor.invoke(ServiceTCCLInterceptor.java:53)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.eclipse.gemini.blueprint.service.importer.support.LocalBundleContextAdvice.invoke(LocalBundleContextAdvice.java:57)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:133)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:121)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
	at com.sun.proxy.$Proxy1114.getUser(Unknown Source)
	at com.atlassian.jira.plugins.importer.imports.importer.impl.DefaultJiraDataImporter$UserProvider.getUser(DefaultJiraDataImporter.java:1577)
	at com.atlassian.jira.plugins.importer.external.ExternalUserUtils$1.apply(ExternalUserUtils.java:117)
	at com.atlassian.jira.plugins.importer.external.ExternalUserUtils$1.apply(ExternalUserUtils.java:114)
	at com.google.common.collect.Iterators$7.computeNext(Iterators.java:652)
	at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:143)
	at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:138)
	at com.atlassian.jira.plugins.importer.external.ExternalUserUtils.checkInvalidUsernames(ExternalUserUtils.java:122)
	at com.atlassian.jira.plugins.importer.external.ExternalUserUtils.prepareUsers(ExternalUserUtils.java:107)
	at com.atlassian.jira.plugins.importer.imports.importer.impl.DefaultJiraDataImporter.importUsers(DefaultJiraDataImporter.java:565)
	at com.atlassian.jira.plugins.importer.imports.importer.impl.DefaultJiraDataImporter.doImport(DefaultJiraDataImporter.java:345)
	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:497)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
	at org.eclipse.gemini.blueprint.service.importer.support.internal.aop.ServiceInvoker.doInvoke(ServiceInvoker.java:56)
	at org.eclipse.gemini.blueprint.service.importer.support.internal.aop.ServiceInvoker.invoke(ServiceInvoker.java:60)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:133)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:121)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.eclipse.gemini.blueprint.service.util.internal.aop.ServiceTCCLInterceptor.invokeUnprivileged(ServiceTCCLInterceptor.java:70)
	at org.eclipse.gemini.blueprint.service.util.internal.aop.ServiceTCCLInterceptor.invoke(ServiceTCCLInterceptor.java:53)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.eclipse.gemini.blueprint.service.importer.support.LocalBundleContextAdvice.invoke(LocalBundleContextAdvice.java:57)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.doProceed(DelegatingIntroductionInterceptor.java:133)
	at org.springframework.aop.support.DelegatingIntroductionInterceptor.invoke(DelegatingIntroductionInterceptor.java:121)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
	at com.sun.proxy.$Proxy1471.doImport(Unknown Source)
	at com.atlassian.jira.plugins.importer.imports.importer.impl.ImporterCallable.call(ImporterCallable.java:26)
	at com.atlassian.jira.plugins.importer.imports.importer.impl.ImporterCallable.call(ImporterCallable.java:15)
	at com.atlassian.jira.task.TaskManagerImpl$TaskCallableDecorator.call(TaskManagerImpl.java:458)
	at com.atlassian.jira.task.TaskManagerImpl$TaskCallableDecorator.call(TaskManagerImpl.java:426)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at com.atlassian.jira.task.ForkedThreadExecutor$ForkedRunnableDecorator.run(ForkedThreadExecutor.java:216)
	at java.lang.Thread.run(Thread.java:745)
2016-03-24 14:22:45,821 INFO - No issues need to be reindexed.