AI crashing my game - Based on Epic Live Stream

So I followed the tutorial streamed by Epic Games on implementing AI - Setting Up Advanced AI | Live Training | Unreal Engine - YouTube

The game crashes quite frequently and I was trying to figure out exactly what is the cause. I figured it was my NPCs and when I looked at the crash log I found the following errors:

This appears once right at the top of the log:

[2017.02.22-07.16.29:785][243]LogCharacterMovement:Warning: GetSimulationTimeStep() - Max iterations 8 hit while remaining time 0.096552 > MaxSimulationTimeStep (0.050) for 'BP_NPC_Master11', movement 'Walking'

and this appears directly below the above warning and continues 26 times until the end of the log:

[2017.02.22-07.16.30:372][275]LogScriptCore:Warning: [2017.02.22-07.16.30:372][275]LogScriptCore:Warning: Script Msg: Attempted to access index 0 from array LastSensedStimuli of length 0! [2017.02.

Unfortunately I’m really new to ai so I have no idea what either of the warnings mean. I’m guessing the bottom one is what’s causing the hard lock though since it repeats 26 times before the game freezes and I have to Alt Tab out.
Apparently it’s looking for a value inside an array but the array is empty?

I’m running 4.13 because I ran into an issue in 4.14 with a previous project so I was hoping to avoid upgrading because 4.13 was the last really stable release for me.

Can you post the callstack of the crash?

Hi MieszkoZ,
I’m not exactly sure what a callstack is but here are my two log fileslink text
link text

I thought I should mention that I’m simulating 30 AI in the level so maybe the problem is that this ai is too complex for that many NPCs? It’s strange though because the crash is completely random. Sometimes I’ll play a match no problem and then other times when I reset the level, it’ll crash on the 2nd or third try. Usually it doesn’t crash until the level has been reset at least once.

Hi Mieszko,
Any chance you had an opportunity to look at the log files and possibly point me in the right direction? I was hoping to get the problem solved this week as I want to release my project this weekend and the AI crash is the last issue.

Thanks!