ios transporter交付ipa报错 could not download，请问这是什么原因呢

HbuilderX3.2.9云打包ipa,transporter交付时报错，这是什么原因呢？
<main> ERROR: could not download
java.io.IOException: The directory: /Users/james/Library/Caches/com.apple.amp.itmstransporter/obr/2.2.0.21, is currenly locked by another process: 38435
at com.apple.transporter.launcher.util.DirectoryLock.lock(DirectoryLock.java:42)
at com.apple.transporter.launcher.asu.ResourceDownloader.lock(ResourceDownloader.java:47)
at com.apple.transporter.launcher.asu.SoftwareUpdater.download(SoftwareUpdater.java:113)
at com.apple.transporter.bootstrap.BootstrapperPhase1.performSoftwareUpdate(BootstrapperPhase1.java:388)
at com.apple.transporter.bootstrap.BootstrapperPhase1.realBootstrap(BootstrapperPhase1.java:194)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:86)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:107)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:78)
at com.apple.transporter.launcher.Launcher.launchBootstrapper(Launcher.java:37)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.apple.transporter.launcher.Application.start(Application.java:450)
at com.apple.transporter.launcher.Application.main(Application.java:947)
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.apple.transporter.launcher.Application.start(Application.java:450)
at com.apple.transporter.launcher.Application.main(Application.java:947)
Caused by: java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:107)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:78)
at com.apple.transporter.launcher.Launcher.launchBootstrapper(Launcher.java:37)
... 6 more
Caused by: java.lang.NullPointerException
at com.apple.transporter.bootstrap.BootstrapperPhase2.bootstrapBundles(BootstrapperPhase2.java:284)
at com.apple.transporter.bootstrap.BootstrapperPhase2.start(BootstrapperPhase2.java:163)
at com.apple.transporter.bootstrap.BootstrapperPhase1.startOSGiFramework(BootstrapperPhase1.java:395)
at com.apple.transporter.bootstrap.BootstrapperPhase1.realBootstrap(BootstrapperPhase1.java:221)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:86)
... 13 more