MetaHumanForMaya 5.8 Expression Editor crashes Maya (CPU without BMI2 instructions)

Hey,

At the studio we’ve recently experienced a crash regarding the Expresssion Editor on MetahumanForMaya 1.3.1 (5.8 compilant). The steps to find this problem are simple:

1. Launch Maya 2026.3.2 (that's our current used version)
2. Load MetahumanForMaya 1.3.1
3. Open up Metahuman Expression Editor
4. Maya immediately crashes

I’ve checked log dumps to see what’s happening, and it points out to this:

STACK_COMMAND: ~0s; .ecxr ; kb

IP_IN_PAGED_CODE: 
nlstools+d717
00007ffb`273fd717 c4e2f3f7c8      shrx    rcx,rax,rcx

SYMBOL_NAME:  nlstools+d717

MODULE_NAME: nlstools

IMAGE_NAME:  nlstools.pyd

FAILURE_BUCKET_ID:  ILLEGAL_INSTRUCTION_c000001d_nlstools.pyd!Unknown

OS_VERSION:  10.0.17763.1

BUILDLAB_STR:  rs5_release

OSPLATFORM_TYPE:  x64

OSNAME:  Windows 10

FAILURE_ID_HASH:  {9ffc44d3-513b-944f-057c-6e1fa7cb0100}

The editor was tested on several PCs, and the only problematic configuration was this CPU: Intel i7-3820. As far as I understand, shrx is a BMI2 instruction, which is missing on this old CPU, hence why it crashes. I’ve tested it on several latest AMD5 CPUs and I couldn’t reproduce.

I didn’t know we run such an old CPU in one of the workstations, but I believe there should be some kind of generic implementation/fallback without BMI2 or it should detect and report missing features so TDs can catch them rather than crashing Maya.

We’ve migrated from 1.2.50 to 1.3.1, where it wasn’t happening.

I can provide whole Maya crash dump and additional system information if required.