I first thought it was just the NLAW causing it, hence the file names in the attachments.
But after investigating it further, i noticed this happens (at least to me) with every weapon(rifle/AT/pistol) in the box, as long as i am taking the weapon into an empty gear slot.
If i just replace my weapon with another from ammobox (with right clicking it), no crash happens.
I did not try if dragging the weapon instead of right clicking makes any difference.