Crash occurs after pausing and unpausing cinematic after restart level

This was tested on Windows the crash does not occur. This crash also occurs on Matinee cinematic as well, but only when you ~ quit the standalone game.

1. Open Elemental Cave Demo on a Mac
2. ~ Pause
3. ~ RestartLevel
4. ~ Pause
5. ~Pause
6. Observe

Result: The standalone game crashes

Expected: The cinematic resumes properly without crashes.

MachineId:67E660359A4D075E27C6A68C5C0E6E19
EpicAccountId:73cc87fb186c41679297faf5c1aa7dd8

SEGV_MAPERR at 0x3

FGenericPlatformMisc::RaiseException(unsigned int) Address = 0x10e5d24bb [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMisc.cpp, line 300] [in UE4Editor-Core.dylib]
FOutputDeviceMacError::Serialize(wchar_t const*, ELogVerbosity::Type, FName const&) Address = 0x10e788562 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/Mac/MacPlatformOutputDevices.cpp, line 93] [in UE4Editor-Core.dylib]
FOutputDevice::Logf(wchar_t const*, ...) Address = 0x10e875367 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/Misc/OutputDevice.cpp, line 68] [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...) Address = 0x10e78a6f1 [Runtime/Core/Public/Containers/ContainerAllocationPolicies.h, line 366] [in UE4Editor-Core.dylib]
FCoreAudioSoundSource::DetachFromAUGraph() Address = 0x130baa710 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Mac/CoreAudio/Private/CoreAudioSource.cpp, line 901] [in UE4Editor-CoreAudio.dylib]
FCoreAudioSoundSource::Stop() Address = 0x130baa30a [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Mac/CoreAudio/Private/CoreAudioSource.cpp, line 424] [in UE4Editor-CoreAudio.dylib]
FAudioDevice::StopSources(TArray<FWaveInstance*, FDefaultAllocator>&, int) Address = 0x10fd4fcb9 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Engine/Private/AudioDevice.cpp, line 2755] [in UE4Editor-Engine.dylib]
FAudioDevice::Update(bool) Address = 0x10fd528b0 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Engine/Private/AudioDevice.cpp, line 3020] [in UE4Editor-Engine.dylib]
TGraphTask<FFunctionGraphTask>::ExecuteTask(TArray<FBaseGraphTask*, FDefaultAllocator>&, ENamedThreads::Type) Address = 0x10fd8ee1c [Runtime/Core/Public/Templates/Function.h, line 120] [in UE4Editor-Engine.dylib]
FNamedTaskThread::ProcessTasksNamedThread(int, bool) Address = 0x10e60a001 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/Async/TaskGraph.cpp, line 259] [in UE4Editor-Core.dylib]
FNamedTaskThread::ProcessTasksUntilQuit(int) Address = 0x10e605aa5 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformProcess.cpp, line 504] [in UE4Editor-Core.dylib]
FTaskGraphImplementation::ProcessThreadUntilRequestReturn(ENamedThreads::Type) Address = 0x10e602321 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/Async/TaskGraph.cpp, line 1725] [in UE4Editor-Core.dylib]
AudioThreadMain(FEvent*) Address = 0x10fd6ef95 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Engine/Private/AudioThread.cpp, line 86] [in UE4Editor-Engine.dylib]
FAudioThread::Run() Address = 0x10fd6f427 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Engine/Private/AudioThread.cpp, line 203] [in UE4Editor-Engine.dylib]
FRunnableThreadPThread::Run() Address = 0x10e64fae3 [/Users/build/Build/++UE4+Main+Compile/Sync/Engine/Source/Runtime/Core/Private/HAL/PThreadRunnableThread.cpp, line 25] [in UE4Editor-Core.dylib]
FRunnableThreadPThread::_ThreadProc(void*) Address = 0x10e61efa1 [Runtime/Core/Private/GenericPlatform/../HAL/PThreadRunnableThread.h, line 166] [in UE4Editor-Core.dylib]
_pthread_body Address = 0x7fff8897399d (filename not found) [in libsystem_pthread.dylib]
_pthread_body Address = 0x7fff8897391a (filename not found) [in libsystem_pthread.dylib]
thread_start Address = 0x7fff88971351 (filename not found) [in libsystem_pthread.dylib]