What causes this exception?
[2020-03-19 18:21:30 CST] <main> INFO: iTMSTransporter : iTunes Store Transporter [2.0.0]
[2020-03-19 18:21:30 CST] <main> INFO: OS identifier: Mac OS X 10.15 (x86_64); jvm=25.71-b02; jre=1.8.0-u131-b11-iTMSTransporter-b02
[2020-03-19 18:21:30 CST] <main> INFO: Memory: [JVM] 1032M free, 1074M total, 1820M max [System] (Physical) 1909M free, 8192M total (Swap) 959M free, 1024M total
[2020-03-19 18:21:30 CST] <main> DBG-X: Memory: [JVM] 1032M free, 1074M total, 1820M max [System] (Physical) 1910M free, 8192M total (Swap) 959M free, 1024M total
[2020-03-19 18:21:30 CST] <main> DBG-X: Using operation named: authenticateForSession
[2020-03-19 18:21:30 CST] <main> DBG-X: Apple's web service operation input parameters:
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter Application = iTMSTransporter
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter BaseVersion = 1.13.0
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter OSIdentifier = Mac OS X 10.15 (x86_64); jvm=25.71-b02; jre=1.8.0-u131-b11-iTMSTransporter-b02
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter StatisticsClientStartDateTimeZoneISO = 2020-03-19T18:21:30+08:00
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter StatisticsPreviousCallDurationInSecs = 1.102685318
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter TransporterArguments = -m upload -u aliyun.living.link@gmail.com -p **hidden value** -v eXtreme -assetFile IMSiLopApp-Release.ipa
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter Version = 2.0.0
[2020-03-19 18:21:30 CST] <main> DBG-X: parameter iTMSTransporterMode = upload
[2020-03-19 18:21:30 CST] <main> INFO: id = 20200319182130-172
[2020-03-19 18:21:30 CST] <main> INFO: iTMSTransporter Correlation Key: 727ecb5f-4e6b-4ed1-8012-5866771b4adf-0001
[2020-03-19 18:21:31 CST] <main> DBG-X: Apple's web service operation return value:
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter SharedSecret = **hidden value**
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter MultipartUploadsEnabled = true
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter EnableJWTForAllCalls = false
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter TxHeaders = {jenga=true}
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter SessionExpiration = 2020-03-23T10:21:31.783Z
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter SessionId = CJOqDBIQnacKjLeuRGCtg3rQ4MaC7Q==
[2020-03-19 18:21:31 CST] <main> DBG-X: parameter StreamingSettings = {LogStreamingEnabled=true, MultipartUploadsEnabled=true, AssetDescriptionStreamingEnabled=false}
[2020-03-19 18:21:35 CST] <main> ERROR: iTMSTransporter could not generate an itmsp: null
[2020-03-19 18:21:35 CST] <main> ERROR: An exception has occurred: null
[2020-03-19 18:21:35 CST] <main> DEBUG: java.lang.NullPointerException
at com.apple.transporter.operation.DeveloperAPIUpload.lambda$generatePackage$1(DeveloperAPIUpload.java:374)
at java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:267)
at java.util.Spliterators$ArraySpliterator.tryAdvance(Spliterators.java:958)
at java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:126)
at java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:498)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:485)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:464)
at com.apple.transporter.operation.DeveloperAPIUpload.generatePackage(DeveloperAPIUpload.java:390)
at com.apple.transporter.operation.DeveloperAPIUpload.execute(DeveloperAPIUpload.java:236)
at com.apple.transporter.Application.reallyBegin(Application.java:224)
at com.apple.transporter.Application.begin(Application.java:114)
at com.apple.transporter.osgi.TransporterService.start(TransporterService.java:87)
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 com.apple.transporter.starter.TransporterStarter.runService(TransporterStarter.java:476)
at com.apple.transporter.starter.TransporterStarter.runTransporterService(TransporterStarter.java:450)
at com.apple.transporter.starter.TransporterStarter.start(TransporterStarter.java:188)
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 com.apple.transporter.bootstrap.BootstrapperPhase2.runStartable(BootstrapperPhase2.java:355)
at com.apple.transporter.bootstrap.BootstrapperPhase2.runStarter(BootstrapperPhase2.java:317)
at com.apple.transporter.bootstrap.BootstrapperPhase2.start(BootstrapperPhase2.java:130)
at com.apple.transporter.bootstrap.BootstrapperPhase1.startOSGiFramework(BootstrapperPhase1.java:321)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:99)
at com.apple.transporter.bootstrap.BootstrapperPhase1.bootstrap(BootstrapperPhase1.java:59)
at com.apple.transporter.launcher.Launcher.launchBootstrapper(Launcher.java:37)
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 com.apple.transporter.launcher.Application.start(Application.java:220)
at com.apple.transporter.launcher.Application.main(Application.java:658)
[2020-03-19 18:21:36 CST] <main> DBG-X: Returning 1