Crash in OS X Editor when working with BSP

I just updated to 4.11.1 on OS X. I’m using the binary version.

I’ve been getting a consistent crash when working with BSP. Everything will be fine until I start to fly the camera around the map; there will be a flash, some of the polygons in the BSP turn yellow, and the Editor crashes. The crash only happens when flying around the map.

Here’s what the Crash Reporter says:

 SEGV_MAPERR at 0x3

FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x107a6f31b [/Users/build/BuildFarm/build_++UE4+Release-4.11/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMisc.cpp, line 294] [in UE4Editor-Core.dylib]
FOutputDeviceMacError::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x107c00ee6 [/Users/build/BuildFarm/build_++UE4+Release-4.11/Engine/Source/Runtime/Core/Private/Mac/MacPlatformOutputDevices.cpp, line 93] [in UE4Editor-Core.dylib]
FOutputDevice::Logf(wchar_t const*, ...) Address = 0x107cf56f7 [/Users/build/BuildFarm/build_++UE4+Release-4.11/Engine/Source/Runtime/Core/Private/Misc/OutputDevice.cpp, line 149] [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...) Address = 0x107cc39c4 [Runtime/Core/Public/Containers/ContainerAllocationPolicies.h, line 340] [in UE4Editor-Core.dylib]
___ZN17FMetalCommandList6CommitEPU27objcproto16MTLCommandBuffer11objc_objectb_block_invoke Address = 0x13c7342a0 [/Users/build/BuildFarm/build_++UE4+Release-4.11/Engine/Source/Runtime/Apple/MetalRHI/Private/MetalCommandList.cpp, line 51] [in UE4Editor-MetalRHI.dylib]
-[_MTLCommandBuffer didComplete:error:] Address = 0x7fff902295e8 (filename not found) [in Metal]
-[MTLIOAccelCommandBuffer didComplete:error:] Address = 0x7fff90201ee1 (filename not found) [in Metal]
-[_MTLCommandQueue commandBufferDidComplete:timestamp:error:] Address = 0x7fff9022d155 (filename not found) [in Metal]
ioAccelCommandQueueBlockFenceCallback Address = 0x7fff8943c1f2 (filename not found) [in IOAccelerator]
IODispatchCalloutFromCFMessage Address = 0x7fff92cb66a2 (filename not found) [in IOKit]
_IODispatchCalloutWithDispatch Address = 0x7fff92cb6721 (filename not found) [in IOKit]
dispatch_mig_server Address = 0x7fff8340ba4b (filename not found) [in libdispatch.dylib]
_dispatch_client_callout Address = 0x7fff833f740b (filename not found) [in libdispatch.dylib]
_dispatch_source_latch_and_call Address = 0x7fff83407675 (filename not found) [in libdispatch.dylib]
_dispatch_source_invoke Address = 0x7fff833fba83 (filename not found) [in libdispatch.dylib]
_dispatch_queue_drain Address = 0x7fff833fc200 (filename not found) [in libdispatch.dylib]
_dispatch_queue_invoke Address = 0x7fff83402707 (filename not found) [in libdispatch.dylib]
_dispatch_root_queue_drain Address = 0x7fff833fad53 (filename not found) [in libdispatch.dylib]
_dispatch_worker_thread3 Address = 0x7fff833fab00 (filename not found) [in libdispatch.dylib]
_pthread_wqthread Address = 0x7fff814a04de (filename not found) [in libsystem_pthread.dylib]
start_wqthread Address = 0x7fff8149e341 (filename not found) [in libsystem_pthread.dylib]

Hello JonathanADaley,

We appreciate you taking the time to report this issue, and in order for us to effectively assist you we need a bit more information in regards to the crash.

We ask that you take a look at our How to Report a Bug sticky on the forums, for instructions on providing me with the necessary information in order to begin the troubleshooting process.

Once you have provided us with some reproducible steps, your crash logs, and any other pertinent information we can continue forward.

Thank you,