Crash on project startup, please help if you can

Here is the log to the crash:


Assertion failed: [File:/Users/build/Build/++UE4/Sync/Engine/Source/Runtime/Apple/MetalRHI/Private/MetalCommandList.cpp] [Line: 192] Command Buffer Scene Failed with Internal Error! Error Domain: MTLCommandBufferErrorDomain Code: 1 Description Internal Error (IOAF code -536870211) Unknown Unknown

FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x108767d1b (filename not found) [in UE4Editor-Core.dylib]
FMacErrorOutputDevice::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x1088c19a0 (filename not found) [in UE4Editor-Core.dylib]
FOutputDevice::LogfImpl(wchar_t const*, …) Address = 0x1089ab829 (filename not found) [in UE4Editor-Core.dylib]
AssertFailedImplV(char const*, char const*, int, wchar_t const*, __va_list_tag*) Address = 0x10893b0fd (filename not found) [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, …) Address = 0x10893b24b (filename not found) [in UE4Editor-Core.dylib]
ReportMetalCommandBufferFailure(mtlpp::CommandBuffer const&, wchar_t const*, bool) Address = 0x133e0cef7 (filename not found) [in UE4Editor-MetalRHI.dylib]
MetalCommandBufferFailureInternal(mtlpp::CommandBuffer const&) Address = 0x133e4c88c (filename not found) [in UE4Editor-MetalRHI.dylib]
HandleMetalCommandBufferError(mtlpp::CommandBuffer const&) Address = 0x133e0b19b (filename not found) [in UE4Editor-MetalRHI.dylib]
HandleIntelMetalCommandBufferError(mtlpp::CommandBuffer const&) Address = 0x133e0b125 (filename not found) [in UE4Editor-MetalRHI.dylib]
FMetalCommandList::HandleMetalCommandBufferFailure(mtlpp::CommandBuffer const&) Address = 0x133e0af65 (filename not found) [in UE4Editor-MetalRHI.dylib]
invocation function for block in FMetalCommandList::Commit(mtlpp::CommandBuffer&, TArray<ns::Object<void (mtlpp::CommandBuffer const&) block_pointer, (ns::CallingConvention)1>, TSizedDefaultAllocator<32> >, bool, bool) Address = 0x133e0d8cf (filename not found) [in UE4Editor-MetalRHI.dylib]
invocation function for block in mtlpp::CommandBuffer::AddCompletedHandler(void (mtlpp::CommandBuffer const&) block_pointer) Address = 0x133dbe984 (filename not found) [in UE4Editor-MetalRHI.dylib]
_doMTLDispatch Address = 0x7fff38fc9711 (filename not found) [in Metal]
-[_MTLCommandBuffer didCompleteWithStartTime:endTime:error:] Address = 0x7fff38fc9c04 (filename not found) [in Metal]
-[MTLIOAccelCommandBuffer didCompleteWithStartTime:endTime:error:] Address = 0x7fff38fc99fe (filename not found) [in Metal]
-[_MTLCommandQueue commandBufferDidComplete:startTime:completionTime:error:] Address = 0x7fff38fc98ed (filename not found) [in Metal]
__53-[MTLIOAccelCommandQueue submitCommandBuffers:count:]_block_invoke.25 Address = 0x7fff38fc97dc (filename not found) [in Metal]
ioAccelCommandQueueBlockFenceCallback Address = 0x7fff517bf6d2 (filename not found) [in IOAccelerator]
IODispatchCalloutFromCFMessage Address = 0x7fff36d537ab (filename not found) [in IOKit]
_IODispatchCalloutWithDispatch Address = 0x7fff36d5362d (filename not found) [in IOKit]
dispatch_mig_server Address = 0x7fff6038fbde (filename not found) [in libdispatch.dylib]
_dispatch_client_callout Address = 0x7fff6037963d (filename not found) [in libdispatch.dylib]
_dispatch_continuation_pop Address = 0x7fff6037bde6 (filename not found) [in libdispatch.dylib]
_dispatch_source_invoke Address = 0x7fff6038af42 (filename not found) [in libdispatch.dylib]
_dispatch_lane_serial_drain Address = 0x7fff6037f792 (filename not found) [in libdispatch.dylib]
_dispatch_lane_invoke Address = 0x7fff60380396 (filename not found) [in libdispatch.dylib]
_dispatch_workloop_worker_thread Address = 0x7fff603886ed (filename not found) [in libdispatch.dylib]
_pthread_wqthread Address = 0x7fff605b9611 (filename not found) [in libsystem_pthread.dylib]
start_wqthread Address = 0x7fff605b93fd (filename not found) [in libsystem_pthread.dylib]
Unknown() Address = 0x2000600050009 (filename not found) [in ???]

This has been fixed after I restarted my mac, very weird.

Very strange indeed…same issue, same simple solution. Thanks mate!

Getting the same error on trying to execute a Development Build, not the Editor. Restarting didn’t work for me in my case.