Threat Window Not Visible on New Toon

[Bhayar]

Have the oddest problem occurring with a "new" toon--my assassin. The Threat window does not show on the screen, even though it's visible on my other 14. I've cross checked settings for this toon vs. the others and I see no variance. I've made sure there's no hidden fields that might cover or block it, but nothing seems to correct the problem--even after hitting the reset button. I'm at a complete loss to figure out what's causing the problem.
Any thoughts?