Crash when Matinee with 2 Event Tracks stopped from one of the Event Tracks

When stopping a Matinee from an Event Track via the level blueprint, if you have 2 Event Tracks the editor will crash.

Also Reproduced in Main Promotable-CL-2479729

1. Add Attached 'TestMatineeStopCrash.umap' file to QAGame Content
2. Open QAGame Editor
3. Open the 'TestMatineeStopCrash.umap' Level
4. PIE

RESULTS: CRASH

EXPECTED: Matinee Stops and Player control resumes

Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 678]
Array index out of bounds: 2 from an array of size 0

KERNELBASE.dll

{0x000007fefcea940d}

+ 0 bytes
UE4Editor-Core.dll!FOutputDeviceWindowsError::Serialize()

{0x000007fed42d8cf4}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Core.dll!FOutputDevice::Logf__VA()

{0x000007fed4123d78}

+ 159 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Core.dll!FError::FinalLogf()

{0x000007fed410f132}

+ 65 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Engine.dll!UInterpGroup::UpdateGroup()

{0x000007fec677cb1c}

+ 131 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!AMatineeActor::UpdateInterp()

{0x000007fec677d828}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!AMatineeActor::StepInterp()

{0x000007fec677b0db}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!AMatineeActor::Tick()

{0x000007fec677bd07}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!AActor::TickActor()

{0x000007fec647bb6e}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!FActorTickFunction::ExecuteTick()

{0x000007fec642acee}

+ 31 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!FTickTaskSequencer::FTickFunctionTask::DoTask()

{0x000007fec6c0bd25}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!TGraphTask<FTickTaskSequencer::FTickFunctionTask>::ExecuteTask()

{0x000007fec6c1d71f}

+ 16 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Core.dll!FTaskThread::ProcessTasks()

{0x000007fed4020e3e}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Core.dll!FTaskThread::ProcessTasksUntilQuit()

{0x000007fed402106d}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Core.dll!FTaskGraphImplementation::WaitUntilTasksComplete()

{0x000007fed4047415}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Engine.dll!FTaskGraphInterface::WaitUntilTaskCompletes()

{0x000007fec6c7fa65}

+ 16 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\c
UE4Editor-Engine.dll!FTickTaskSequencer::ReleaseTickGroup()

{0x000007fec6c6082c}

+ 180 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!FTickTaskManager::RunTickGroup()

{0x000007fec6c6e093}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!UWorld::RunTickGroup()

{0x000007fec6877609}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-Engine.dll!UWorld::Tick()

{0x000007fec687e57d}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\e
UE4Editor-UnrealEd.dll!UEditorEngine::Tick()

{0x000007feca7cb966}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\editor\un
UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick()

{0x000007fecad42106}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\editor\un
UE4Editor.exe!FEngineLoop::Tick()

{0x000000013f757f55}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\l
UE4Editor.exe!GuardedMain()

{0x000000013f747f2c}

+ 0 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\l
UE4Editor.exe!GuardedMainWrapper()

{0x000000013f747faa}

+ 5 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\l
UE4Editor.exe!WinMain()

{0x000000013f75b5b8}

+ 17 bytes [d:\buildfarm\buildmachine_++depot+ue4\engine\source\runtime\l
UE4Editor.exe!__tmainCRTStartup()

{0x000000013f75c5e9}

+ 21 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]
kernel32.dll

{0x0000000076c659ed}

+ 0 bytes
ntdll.dll

{0x0000000076e9c541} + 0 bytes
ntdll.dll {0x0000000076e9c541}

+ 0 bytes