Linphone-Xamarinのlinphone_core_iterateのエラーについて

Linphone-Xamarin SDKを用いた、iOSアプリケーション(SIPクライアント)を開発しています。
http://www.linphone.org/news/53/26/Creation-of-a-Liblinphone-C-wrapper-for-Xamarin.html

実行中にアプリが落ちることがあり、
デバッグ中のコンソールには下記のように出力されておりました。
※IDEでは例外は捕捉できていません

アプリが落ちる原因が分からず、困っています。
どなたか教えていただけますでしょうか。
また、有効な対策がございましたら、ご教授願います。
よろしくお願い致します。

なお、linphone_core_iterateは、以下のように実行しております。
・linphone_core_iterateはメインスレッドで実行
・linphone_core_iterateの実行間隔は100ms

コンソール出力

SipClient.iOS[485:481613] critical: Stacktrace:
2018-04-02 21:11:29.786 SipClient.iOS[485:481613] critical: at 2018-04-02 21:11:29.786 SipClient.iOS[485:481613] critical: at (wrapper 2018-04-02 21:11:29.788 SipClient.iOS[485:481613] critical: at Linphone.Core.Iterate 2018-04-02 21:11:29.789 SipClient.iOS[485:481613] critical: at SipClient.App 2018-04-02 21:11:29.791 SipClient.iOS[485:481613] critical: at Foundation.NS 2018-04-02 21:11:29.791 SipClient.iOS[485:481613] critical: at (wrapper 2018-04-02 21:11:29.791 SipClient.iOS[485:481613] critical: at 2018-04-02 21:11:29.792 SipClient.iOS[485:481613] critical: at (wrapper 2018-04-02 21:11:29.793 SipClient.iOS[485:481613] critical: at UIKit.UIApplication.Main 2018-04-02 21:11:29.793 SipClient.iOS[485:481613] critical: at UIKit.UIApplication.Main 2018-04-02 21:11:29.793 SipClient.iOS[485:481613] critical: at SipClient.iOS 2018-04-02 21:11:29.793 SipClient.iOS[485:481613] critical: at (wrapper 2018-04-02 21:11:29.794 SipClient.iOS[485:481613] critical:
Native stacktrace:
2018-04-02 21:11:29.800 SipClient.iOS[485:481613] critical: 0 SipClient.iOS 2018-04-02 21:11:29.800 SipClient.iOS[485:481613] critical: 1 SipClient.iOS 2018-04-02 21:11:29.800 SipClient.iOS[485:481613] critical: 2 libsystem_platform.dylib 2018-04-02 21:11:29.800 SipClient.iOS[485:481613] critical: 3 bctoolbox 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 4 bctoolbox 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 5 linphone 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 6 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 7 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 8 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 9 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 10 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 11 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 12 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 13 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 14 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 15 SipClient.iOS 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 16 Foundation 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 17 CoreFoundation 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 18 CoreFoundation 2018-04-02 21:11:29.801 SipClient.iOS[485:481613] critical: 19 CoreFoundation 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 20 CoreFoundation 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 21 CoreFoundation 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 22 GraphicsServices 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 23 UIKit 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 24 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 25 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 26 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 27 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 28 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 29 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 30 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 31 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 32 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 33 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 34 SipClient.iOS 2018-04-02 21:11:29.802 SipClient.iOS[485:481613] critical: 35 libdyld.dylib 2018-04-02 21:11:29.803 SipClient.iOS[485:481613] critical: --><unknown> <0xffffffff>
managed-to-native) Linphone.Core.linphone_core_iterate (intptr) <0x00007>
() [0x00001] in /Users/pe/Desktop/SipClient/SipClient/SipClient/Lib/LinphoneWrapper.cs:10246
/<>c.<iterate>b__42_0 () [0x00001] in /Users/pe/Desktop/SipClient/SipClient/SipClient/App.xaml.cs:258
AsyncActionDispatcher.Apply () [0x00000] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.8.1.28/src/Xamarin.iOS/Foundation/NSAction.cs:163
runtime-invoke) object.runtime_invoke_dynamic (intptr,intptr,intptr,intptr) [0x0001e] in <77f233cf63384ebaa1d752e479e82a77#FF549F36-3DC2-06BC-37B1-7A31A35146AA>:0
--><unknown> <0xffffffff>
managed-to-native) UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <0x00007>
(string[],intptr,intptr) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.8.1.28/src/Xamarin.iOS/UIKit/UIApplication.cs:79
(string[],string,string) [0x00038] in /Library/Frameworks/Xamarin.iOS.framework/Versions/11.8.1.28/src/Xamarin.iOS/UIKit/UIApplication.cs:63
.Application.Main (string[]) [0x00001] in /Users/pe/Desktop/SipClient/SipClient/SipClient.iOS/Main.cs:17
runtime-invoke) object.runtime_invoke_dynamic (intptr,intptr,intptr,intptr) [0x0001e] in <77f233cf63384ebaa1d752e479e82a77#FF549F36-3DC2-06BC-37B1-7A31A35146AA>:0
0x0000000102a1b298 _ZN7plcrash3BIT5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 214856
0x0000000102a26850 mono_pmip + 9760
0x0000000180affb50 _sigtramp + 52
0x0000000102e791bc bctbx_list_for_each + 32
0x0000000102e791bc bctbx_list_for_each + 32
0x0000000103199694 linphone_core_iterate + 1084
0x00000001013dab90 SipClient.iOS + 977808
0x0000000101344f60 SipClient.iOS + 364384
0x000000010139202c SipClient.iOS + 679980
0x00000001020f5054 SipClient.iOS + 14717012
0x00000001016c0d08 SipClient.iOS + 4017416
0x0000000102a299d0 mono_pmip + 22432
0x0000000102a93128 mono_pmip + 454392
0x0000000102a93084 mono_pmip + 454228
0x00000001012f0204 SipClient.iOS + 16900
0x00000001012f08e8 SipClient.iOS + 18664
0x00000001818d72e4 <redacted> + 340
0x0000000180e8377c <redacted> + 24
0x0000000180e836fc <redacted> + 88
0x0000000180e82f84 <redacted> + 204
0x0000000180e80b5c <redacted> + 1048
0x0000000180da0c58 CFRunLoopRunSpecific + 436
0x0000000182c4cf84 GSEventRunModal + 100
0x000000018a4f95c4 UIApplicationMain + 236
0x0000000102186e10 SipClient.iOS + 15314448
0x00000001021178dc SipClient.iOS + 14858460
0x000000010211789c SipClient.iOS + 14858396
0x000000010138ce80 SipClient.iOS + 659072
0x00000001016c0d08 SipClient.iOS + 4017416
0x0000000102a299d0 mono_pmip + 22432
0x0000000102a93128 mono_pmip + 454392
0x0000000102a95df8 mono_pmip + 465864
0x0000000102a11fcc _ZN7plcrash3BIT5async24dwarf_cfa_state_iteratorIyxE4nextEPjPNS1_28plcrash_dwarf_cfa_reg_rule_tEPy + 177276
0x0000000102b369c0 _Z9__isctypeim + 46228
0x0000000101310694 SipClient.iOS + 149140
0x00000001808c056c <redacted> + 4

Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.

Xamarin.Hosting: Process '485' exited.
Application 'jp.co.hogehoge.AppName' terminated.

開発環境

IDE: VisualStudio for Mac 7.4.1
liblinphone-xamarin-sdkバージョン: 3.12.0
WebViewアプリケーションです。

ソース

    private void LinphoneCoreIterate()
    {
        while (true)
        {
            Thread.Sleep(100);
            try
            {
                // Linphoneの状態を更新する
                iterate(false);
            }
            catch (Exception ex)
            {
                
            }
            Device.BeginInvokeOnMainThread(() =>
            {
                // ログイン状態のチェック
                CheckLoginStatus();
            });
        }
    }

    private static int IterateNum = 0;
    public static void iterate(bool isRefresh) {
        if (IterateNum >= 1 && !isRefresh)
        {
            Thread.Sleep(500);
            return;
        }
        IterateNum++;
        try
        {
            // メインスレッド上で実行する
            Device.BeginInvokeOnMainThread(() =>
            {
                LinphoneCore.Iterate();

            });
        }
        catch(Exception)
        {
        }
        IterateNum--;
    }