问CVM实例列表获取失败？

我只是自己注册一个账号测试，调用查看实例列表失败，总是提示我有一个参数不可用，但是我传的已经是最基本的参数了，而且我试着换了很多参数都不行。

[main] DEBUG [QcApiHelper:65] - before sign : POSTcvm.api.qcloud.com/v2/index.php?Action=DescribeInstances&Nonce=211549270&SecretId=AKIDkLjwwiaYeWBc6NqHuKWUFm6B2g6Ip0Wp&Timestamp=1509586200&Version=2017-03-12

09:30:01,541 [main] DEBUG [QcApiHelper:73] - sign result : 199EomRjpoi/UHooAJ5vrpn1uw4=

09:30:02,879 [main] DEBUG [QcApiHelper:121] - call api:DescribeInstances used 1338ms :

http code = 200

body={"Response":{"Error":{"Code":"InvalidParameter","Message":"A parameter specified in a request is not valid, is unsupported, or cannot be used."},"RequestId":"514fb77e-1d30-03e1-b065-59fa7552f3b2"}}

09:30:02,956 [main] ERROR [CvmApiServiceImpl:193] -

java.lang.NullPointerException

at com.saicstack.paas.qcloud.cvm.service.impl.CvmApiServiceImpl.getDescribeInstances(CvmApiServiceImpl.java:188)

at TestCvmApi.testGetDescribeInstances(TestCvmApi.java:103)

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.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)

at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)

at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:252)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)

at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)

at org.junit.runner.JUnitCore.run(JUnitCore.java:137)

at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)

at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)

at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)

at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)