Random crashes from Animation Blueprints - Pose ContainsNan

I am using the Mannequin Rig, and I’ve started seeing this issue where I’ll randomly hit a breakpoint in the engine on start. It happens extremely inconsistently, I did a test where I could start 4 clients like 30 times in a row without it tripping, but then I restart the engine and now I trip it ever other time I press play.

Visual studio is bringing me to this line 531 of BonePose.h: check(!Pose[BoneIndex].ContainsNaN());

I have a pretty elaborate Animation graph. And if I don’t perform any Modify Bones or TwoBoneIK, then I won’t trip this check. None of the nodes are presenting any warnings.

Unfortunately I can’t even get a Crash Log. All I can seem to get is this output log:

[2017.07.12-21.09.52:633][207]LogWindows:Error: === Critical error: ===
[2017.07.12-21.09.52:633][207]LogWindows:Error: 
[2017.07.12-21.09.52:634][207]LogWindows:Error: Assertion failed: !Pose[BoneIndex].ContainsNaN() [File:d:\unrealengine-4.16.2\engine\source\runtime\engine\public\BonePose.h] [Line: 531] 
[2017.07.12-21.09.52:634][207]LogWindows:Error: 
[2017.07.12-21.09.52:634][207]LogWindows:Error: 
[2017.07.12-21.09.52:634][207]LogWindows:Error: 
[2017.07.12-21.09.52:634][207]LogWindows:Error: 
[2017.07.12-21.09.52:656][207]LogExit: Executing StaticShutdownAfterError
[2017.07.12-21.09.52:656][207]LogWindows: FPlatformMisc::RequestExit(1)
The thread 0x3cc8 has exited with code 0 (0x0).
The thread 0x4fa8 has exited with code 3 (0x3).
The thread 0x3bdc has exited with code 3 (0x3).
The thread 0x370c has exited with code 3 (0x3).
The thread 0x3c60 has exited with code 3 (0x3).
The thread 0x1d14 has exited with code 3 (0x3).
The thread 0x28a4 has exited with code 3 (0x3).
The thread 0x1628 has exited with code 3 (0x3).
The thread 0x42c4 has exited with code 3 (0x3).
The thread 0x2b80 has exited with code 3 (0x3).
The thread 0x32c8 has exited with code 3 (0x3).
The thread 0x4628 has exited with code 3 (0x3).
The thread 0x1818 has exited with code 3 (0x3).
The thread 0x12ec has exited with code 3 (0x3).
The thread 0x2a38 has exited with code 3 (0x3).
The thread 0x2cd0 has exited with code 3 (0x3).
The thread 0x27b0 has exited with code 3 (0x3).
The thread 0x23e4 has exited with code 3 (0x3).
The thread 0xe78 has exited with code 3 (0x3).
The thread 0x1e68 has exited with code 3 (0x3).
The thread 0x52e8 has exited with code 3 (0x3).
The thread 0x4f30 has exited with code 3 (0x3).
The thread 0x4d58 has exited with code 3 (0x3).
The thread 0x2bc8 has exited with code 3 (0x3).
The thread 0x32d0 has exited with code 3 (0x3).
The thread 0x4fdc has exited with code 3 (0x3).
The thread 0x4614 has exited with code 3 (0x3).
The thread 0x1840 has exited with code 3 (0x3).
The thread 0x9ac has exited with code 3 (0x3).
The thread 0x5024 has exited with code 3 (0x3).
The thread 0x29e8 has exited with code 3 (0x3).
The thread 0x1aec has exited with code 3 (0x3).
The thread 0x2e34 has exited with code 3 (0x3).
The thread 0x4f3c has exited with code 3 (0x3).
The thread 0x53bc has exited with code 3 (0x3).
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The thread 0x700 has exited with code 3 (0x3).
The thread 0xa0c has exited with code 3 (0x3).
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The thread 0x4cfc has exited with code 3 (0x3).
The thread 0x2570 has exited with code 3 (0x3).
The thread 0x27e0 has exited with code 3 (0x3).
The thread 0x311c has exited with code 3 (0x3).
The thread 0x36ac has exited with code 3 (0x3).
The thread 0x2354 has exited with code 3 (0x3).
The thread 0x4f58 has exited with code 3 (0x3).
The thread 0xd90 has exited with code 3 (0x3).
The thread 0x49f4 has exited with code 3 (0x3).
The thread 0x524c has exited with code 3 (0x3).
The thread 0x3854 has exited with code 3 (0x3).
The thread 0x501c has exited with code 3 (0x3).
The thread 0x2db8 has exited with code 3 (0x3).
The thread 0x26cc has exited with code 3 (0x3).
The thread 0x52a0 has exited with code 3 (0x3).
The thread 0x4c3c has exited with code 3 (0x3).
The thread 0x52e0 has exited with code 3 (0x3).
The thread 0x52d0 has exited with code 3 (0x3).
The thread 0x51b4 has exited with code 3 (0x3).
The thread 0x3bd8 has exited with code 3 (0x3).
The thread 0x26ec has exited with code 3 (0x3).
The thread 0x2080 has exited with code 3 (0x3).
The thread 0x2914 has exited with code 3 (0x3).
The thread 0x2220 has exited with code 3 (0x3).
The thread 0x1ac0 has exited with code 3 (0x3).
The thread 0x42dc has exited with code 3 (0x3).
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The thread 0x2c44 has exited with code 3 (0x3).
The thread 0x1b1c has exited with code 3 (0x3).
The thread 0x2714 has exited with code 3 (0x3).
The thread 0x3180 has exited with code 3 (0x3).
The thread 0x2f5c has exited with code 3 (0x3).
The thread 0x5068 has exited with code 3 (0x3).
The thread 0x5004 has exited with code 3 (0x3).
The thread 0x2634 has exited with code 3 (0x3).
The thread 0x1f00 has exited with code 3 (0x3).
The thread 0x2c0c has exited with code 3 (0x3).
The thread 0x4c04 has exited with code 3 (0x3).
The thread 0x50f8 has exited with code 3 (0x3).
The thread 0x41b0 has exited with code 3 (0x3).
The thread 0x3a2c has exited with code 3 (0x3).
The thread 0x4f80 has exited with code 3 (0x3).
The thread 0x928 has exited with code 3 (0x3).
The thread 0x30f0 has exited with code 3 (0x3).
The thread 0xae8 has exited with code 3 (0x3).
The thread 0x2ff8 has exited with code 3 (0x3).
The thread 0x4f98 has exited with code 3 (0x3).
The thread 0xa8c has exited with code 3 (0x3).
The thread 0x1024 has exited with code 3 (0x3).
The thread 0x360 has exited with code 3 (0x3).
The thread 0x50ec has exited with code 3 (0x3).
The thread 0x3ca4 has exited with code 3 (0x3).
The thread 0x34d8 has exited with code 3 (0x3).
The thread 0x5338 has exited with code 3 (0x3).
The thread 0x50c0 has exited with code 3 (0x3).
The thread 0x5044 has exited with code 3 (0x3).
The thread 0x4ef4 has exited with code 3 (0x3).
The thread 0x998 has exited with code 3 (0x3).
The thread 0x522c has exited with code 3 (0x3).
The thread 0x528c has exited with code 3 (0x3).
The thread 0x2eac has exited with code 3 (0x3).
The thread 0x3b58 has exited with code 3 (0x3).
The thread 0x5054 has exited with code 3 (0x3).
The thread 0x1db8 has exited with code 3 (0x3).
The thread 0x48d8 has exited with code 3 (0x3).
The thread 0x53c0 has exited with code 3 (0x3).
The thread 0x4984 has exited with code 3 (0x3).
The thread 0xca8 has exited with code 3 (0x3).
The thread 0x51a8 has exited with code 3 (0x3).
The thread 0x13c8 has exited with code 3 (0x3).
The thread 0x5174 has exited with code 3 (0x3).
The thread 0x294c has exited with code 3 (0x3).
The thread 0x3710 has exited with code 3 (0x3).
The thread 0x12a4 has exited with code 3 (0x3).
The thread 0x2b88 has exited with code 3 (0x3).
The thread 0x650 has exited with code 3 (0x3).
The thread 0x2940 has exited with code 3 (0x3).
The thread 0x5178 has exited with code 3 (0x3).
The thread 0x2c38 has exited with code 3 (0x3).
The thread 0x2df0 has exited with code 3 (0x3).
The thread 0xce0 has exited with code 3 (0x3).
The thread 0x5350 has exited with code 3 (0x3).
The thread 0x45d8 has exited with code 3 (0x3).
The thread 0x70 has exited with code 3 (0x3).
The thread 0x4a44 has exited with code 3 (0x3).
The thread 0x536c has exited with code 3 (0x3).
The thread 0x53fc has exited with code 3 (0x3).
The thread 0x4ff0 has exited with code 3 (0x3).
The thread 0x389c has exited with code 3 (0x3).
The thread 0x2510 has exited with code 3 (0x3).
The thread 0x5374 has exited with code 3 (0x3).
The thread 0x244c has exited with code 3 (0x3).
The thread 0x2078 has exited with code 3 (0x3).
The thread 0x4b18 has exited with code 3 (0x3).
The thread 0x444 has exited with code 3 (0x3).
The thread 0x3d10 has exited with code 3 (0x3).
The thread 0x19f8 has exited with code 3 (0x3).
The thread 0x5330 has exited with code 3 (0x3).
The thread 0xe8c has exited with code 3 (0x3).
The thread 0x3628 has exited with code 3 (0x3).
The thread 0x1310 has exited with code 3 (0x3).
The program '[19564] UE4Editor.exe' has exited with code 3 (0x3).