我在AppStore上有一个实时应用，该应用使用Facebook Audience Network（FAN）来展示广告。实时版本使用FAN SDK v 4.26.0，并成功显示了原生广告和非页内广告。但是，该应用程序的最新开发版本使用FAN SDK v 4.99.1。插页式广告和原生广告使用相同的广告展示位置ID。即使该应用正在获取广告，但经过一段时间提示该广告无效的异常后也会崩溃。
@media (min-width: 1192px) {
.modal-xl .modal-content .modal-body {
min-height: 73vh;
max-height: 73vh;
height: 100%;
}
这是崩溃日志：
Uncaught exception: Native ad <FBNativeAd: 0x180a7d60> passed to <FBAdGenericHeight300View: 0x180c9360;
frame = (0 0; 0 0); layer = <CALayer: 0x182916b0>>, but the native ad is not valid.
我正在使用官方Facebook开发人员网站上提到的最新示例代码。
OS Version: iPhone OS 10.3.3 (14G60)
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Triggered by Thread: 0
Application Specific Information:
abort() called
Filtered syslog:
None found
Last Exception Backtrace:
0 CoreFoundation 0x1cc2fb38 __exceptionPreprocess + 124
1 libobjc.A.dylib 0x1beb7062 objc_exception_throw + 33
2 CoreFoundation 0x1cc2fa80 +[NSException raise:format:] + 103
3 MyAwesomeApp 0x0036c744 -[FBNativeAdView initWithNativeAd:withType:withAttributes:] + 3438404 (FBNativeAdView.m:88)
4 MyAwesomeApp 0x0036c48e +[FBNativeAdView nativeAdViewWithNativeAd:withType:withAttributes:] + 3437710 (FBNativeAdView.m:67)
5 MyAwesomeApp 0x0036c418 +[FBNativeAdView nativeAdViewWithNativeAd:withType:] + 3437592 (FBNativeAdView.m:61)
6 MyAwesomeApp 0x0003ac0e -[MyAwesomeApp nativeAdDidLoad:] + 89102 (SearchViewController.m:2659)
7 MyAwesomeApp 0x00360c76 -[FBNativeAd nativeAdBaseDidLoad:] + 3390582 (FBNativeAd.m:138)
8 MyAwesomeApp 0x0036242c __90-[FBNativeAdBase displayAdController:presentedData:onImpression:onImpressionMiss:onClick:]_block_invoke + 3396652 (FBNativeAdBase.m:337)
9 MyAwesomeApp 0x00361fea __51-[FBNativeAdBase downloadMediaFromData:completion:]_block_invoke_2 + 3395562 (FBNativeAdBase.m:301)
10 libdispatch.dylib 0x1c2fd792 _dispatch_call_block_and_release + 5
11 libdispatch.dylib 0x1c2fd77e _dispatch_client_callout + 17
12 libdispatch.dylib 0x1c301d00 _dispatch_main_queue_callback_4CF + 897
13 CoreFoundation 0x1cbebd64 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 3
14 CoreFoundation 0x1cbe9e14 __CFRunLoopRun + 843
15 CoreFoundation 0x1cb3d1aa CFRunLoopRunSpecific + 465
16 CoreFoundation 0x1cb3cfcc CFRunLoopRunInMode + 99
17 GraphicsServices 0x1e2e7b3c GSEventRunModal + 75
18 UIKit 0x21ec5a4e UIApplicationMain + 145
19 MyAwesomeApp 0x000c1db4 main + 642484 (main.m:14)
20 libdyld.dylib 0x1c32a4e6 _dyld_process_info_notify_release + 25
请有人帮我弄清楚这个问题吗？