A crash can occur while cooking in 4.18 in ispc_texcomp.dll. This was reported as being the result of an instruction that is only available for "Haswell and newer Intel CPUs." Pre-Haswell CPU's will crash when this instruction runs.
Rebuilding ispc_texcomp.dll with the latest from Intel appears to resolve this issue.
This also occurs on our internal carts, which aren't pre-Haswell. So far it has not occurred on anyone's Xenon chips in Engine QA.
Unable to repro internally. Requires a pre-Haswell CPU, which we are not sure we have available.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-52281 in the post.