Native crash with Xamarin.Mac 2.8 using binding library (created with bmac)

Hello,

Our company has a Xamarin.Mac application which uses the Classic API. Currently we're using the following components with Mac OS X 10.11.6

=== Xamarin Studio Enterprise ===

Version 5.10.3 (build 51)
Installation UUID: f34adbd6-1479-46c4-84fb-ee0d1d8e6bde
Runtime:
    Mono 4.2.3 (explicit/832de4b)
    GTK+ 2.24.23 (Raleigh theme)

    Package version: 402030004

=== Xamarin.Mac ===

Version: 2.4.2.1 (Xamarin Enterprise)

We plan to update to the latest stable versions and I made a try to check if the application is still working built with Xamarin Studio 6 and Xamarin.Mac 2.8. I have also updated Mono to 4.4.1.

After the update our solution was loaded and compiled successfully and basically it was running fine, but we have a library that is a binding library to the native ImageCaptureCore framework that was created with bmac which is not working correctly. At a given point a callback from the ImageCaptureCore causes an application crash:

Exception Type:        EXC_BAD_ACCESS (SIGABRT)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000069727453
Exception Note:        EXC_CORPSE_NOTIFY

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib          0x9c96f572 __pthread_kill + 10
1   libsystem_pthread.dylib         0x97e03654 pthread_kill + 101
2   libsystem_c.dylib               0x9b6ecc38 abort + 156
3   com.Canon.iristaUploader        0x001b12a5 mono_handle_native_sigsegv + 757
4   com.Canon.iristaUploader        0x00142a62 mono_arch_handle_altstack_exception + 162 (exceptions-x86.c:1097)
5   com.Canon.iristaUploader        0x001bc07e mono_sigsegv_signal_handler + 446 (mini-runtime.c:2489)
6   libsystem_platform.dylib        0x91fb879b _sigtramp + 43
7   ???                             0xffffffff 0 + 4294967295
8   com.Canon.iristaUploader        0x001bbec0 mono_sigill_signal_handler + 48 (mini-runtime.c:2398)
9   com.apple.ImageCaptureCore      0x97f53380 -[ICMasterDeviceBrowser handleCommandCompletion:] + 580
10  libobjc.A.dylib                 0x95a7e3ee -[NSObject performSelector:withObject:] + 70
11  com.apple.ImageCaptureCore      0x97f19bc7 -[ICCommandCenter handleCompletionEvent:replyEvent:] + 460
12  com.apple.ImageCaptureCore      0x97f1ac82 -[ICCommandCenter handleMachMessage:] + 431
13  com.apple.Foundation            0x9c17c156 __NSFireMachPort + 417
14  com.apple.CoreFoundation        0x909c72da __CFMachPortPerform + 330
15  com.apple.CoreFoundation        0x909c7185 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
16  com.apple.CoreFoundation        0x909c70f0 __CFRunLoopDoSource1 + 512
17  com.apple.CoreFoundation        0x909be639 __CFRunLoopRun + 2649
18  com.apple.CoreFoundation        0x909bd976 CFRunLoopRunSpecific + 390
19  com.apple.CoreFoundation        0x909bd7db CFRunLoopRunInMode + 123
20  com.apple.HIToolbox             0x9b2db2f1 RunCurrentEventLoopInMode + 267
21  com.apple.HIToolbox             0x9b2db0f3 ReceiveNextEventCommon + 503
22  com.apple.HIToolbox             0x9b2daeec _BlockUntilNextEventMatchingListInModeWithFilter + 99
23  com.apple.AppKit                0x922382e2 _DPSNextEvent + 1053
24  com.apple.AppKit                0x9223785b -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1057
25  com.apple.AppKit                0x92237432 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 121
26  com.apple.AppKit                0x9222ab47 -[NSApplication run] + 1063
27  com.apple.AppKit                0x921f1469 NSApplicationMain + 1630
28  ???                             0x04bf1f54 0 + 79634260
29  ???                             0x04bf1d30 0 + 79633712
30  ???                             0x00d881bc 0 + 14188988
31  ???                             0x00d88338 0 + 14189368
32  com.Canon.iristaUploader        0x001beeea mono_jit_runtime_invoke + 714 (mini-runtime.c:2345)
33  com.Canon.iristaUploader        0x0028548f mono_runtime_invoke + 127 (object.c:2783)
34  com.Canon.iristaUploader        0x0028b131 mono_runtime_exec_main + 401 (object.c:4038)
35  com.Canon.iristaUploader        0x0028aeea mono_runtime_run_main + 618 (object.c:3666)
36  com.Canon.iristaUploader        0x001397ed mono_jit_exec + 93 (driver.c:1007)
37  com.Canon.iristaUploader        0x0013bb41 mono_main + 7985 (driver.c:2080)
38  com.Canon.iristaUploader        0x000e07be main + 798 (launcher.m:551)
39  libdyld.dylib                   0x9bf7e6ad start + 1

The first question is, can we use the Classic API in the future along with the latest Xamarin.Mac version (and Xamarin Studio)?
If the answer is yes (I suppose), can you help us to find what is causing the crash?

Let me know if any further detail needed.

Thanks
Peter Zsikai