Oops! My apologies but I was assigning material data to the default elements of which there were none! I was importing step files and not paying attention.
All is well, thanks!
Victor, thanks for the quick reply. I just didn't wait long enough when trying to toggle the element edges. The model had a bit over 87,000 elements and I guess my graphics processor wasn't fast enough and I was impatient! I'll learn one day, I hope…