我们正在尝试在Unity中使用Unity制作Android应用程序内结算。我们使用的插件似乎运行良好，我已成功地在旧项目中访问Google的应用内结算服务。但是，当我尝试在我们的新项目（使用测试帐户）中进行测试购买时，我收到此错误：＆＃34; https://android.clients.google.com/fdfe/preparePurchase＆＃34;的意外响应代码403。
我在StackOverflow和Google上搜索了类似的案例，但是我见过的解决方案都没有解决我们的问题。我相信我们所有的设置都应该是正确的： - 我们正在测试的设备已将其主要帐户添加到测试人员列表（在开发者控制台上），而不是Google开发者帐户。 - APK已上传并以alpha格式发布， - 我们正在测试的应用内商品已被激活。 - com.android.vending.BILLING的权限已添加到清单中。
这是我们的日志：
And here is our log:
D/Finsky ( 3814): [407] InAppBillingUtils.getPreferredAccount: [OUR BUNDLE ID]: Account from first account - [J08vUDQx0XyZqx40E-hxtcffLeU]
D/Finsky ( 3814): [407] InAppBillingUtils.getPreferredAccount: [OUR BUNDLE ID]: Account from first account - [J08vUDQx0XyZqx40E-hxtcffLeU]
D/Finsky ( 3814): [407] InAppBillingUtils.getPreferredAccount: [OUR BUNDLE ID]: Account from first account - [J08vUDQx0XyZqx40E-hxtcffLeU]
E/Parcel ( 815): Class not found when unmarshalling: com.google.android.finsky.billing.lightpurchase.PurchaseParams
E/Parcel ( 815): java.lang.ClassNotFoundException: com.google.android.finsky.billing.lightpurchase.PurchaseParams
......
E/Parcel ( 815): at dalvik.system.NativeStart.run(Native Method)
E/Parcel ( 815): Caused by: java.lang.NoClassDefFoundError: com/google/android/finsky/billing/lightpurchase/PurchaseParams
E/Parcel ( 815): ... 19 more
E/Parcel ( 815): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.android.finsky.billing.lightpurchase.PurchaseParams" on path: DexPathList[[directory "."],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
E/Parcel ( 815): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:67)
E/Parcel ( 815): .........
W/ContextImpl( 815): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1478 com.android.server.am.ActivityStack.startPausingLocked:1006 com.android.server.am.ActivityStack.resumeTopActivityLocked:1944 com.android.server.am.ActivityStackSupervisor.resumeTopActivitiesLocked:3054 com.android.server.am.ActivityStackSupervisor.resumeTopActivitiesLocked:3032
W/ContextImpl( 815): Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1478 com.android.server.am.ActivityStackSupervisor.realStartActivityLocked:1160 com.android.server.am.ActivityStackSupervisor.startSpecificActivityLocked:1311 com.android.server.am.ActivityStack.resumeTopActivityLocked:2268 com.android.server.am.ActivityStackSupervisor.resumeTopActivitiesLocked:3054
I/ElegantRequestDirector( 3814): I/O exception (org.apache.http.NoHttpResponseException) caught when processing request: The target server failed to respond
I/ElegantRequestDirector( 3814): Retrying request
W/qdhwcomposer( 276): Excessive delay reading vsync: took 99 ms
E/Volley ( 3814): [415] BasicNetwork.performRequest: Unexpected response code 403 for https://android.clients.google.com/fdfe/preparePurchase
D/Finsky ( 3814): [1] PurchaseFragment.handleError: Error: PurchaseError{type=2 subtype=0}
D/Finsky ( 3814): [1] PurchaseFragment.fail: Purchase failed: PurchaseError{type=2 subtype=0}