[4.7.2] Crash when stopping a matinee with multiple event tracks

I have a matinee sequence with multiple event tracks. My game will crash if I attempt to stop the matinee during one of the matinee events. I am using 4.7.2 from the UE4 launcher.

Repo

My matinee is setup as follows. Note that this matinee sequence has two event tracks:

34314-image1.png

The level blueprint is setup as follows:

34315-image2.png

My game crashes when the Stop node is executed during the Crash event.

[Example Project][3]

Workaround

I found two workarounds:

  1. Only use a single event track
  2. Pause the matinee first and then call stop on another frame. Such as:

Trimmed Crash Callstack

Included for better search results. [Full log file here.][5]

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.7\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 679] 
Array index out of bounds: 2 from an array of size 0
...
UE4Editor-Engine.dll!UInterpGroup::UpdateGroup() (0x000007feda6998f2) + 74 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\interpolation.cpp:1992]
UE4Editor-Engine.dll!AMatineeActor::UpdateInterp() (0x000007feda69a3b0) + 0 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\interpolation.cpp:720]
UE4Editor-Engine.dll!AMatineeActor::StepInterp() (0x000007feda697fdb) + 0 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\interpolation.cpp:1068]
UE4Editor-Engine.dll!AMatineeActor::Tick() (0x000007feda698b97) + 0 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\interpolation.cpp:595]
...

Hi Lee -

Thank you for your report. I was able to easily reproduce this internally and have placed an issue report, for reference UE-11906. As we work toward a solution, I will keep you informed here.

Thank You Again -

Eric Ketchum