Okay, let's tackle this. The user wants me to rewrite the headline about Harry and Meghan's UK visit being canceled. The original headline mentions it was "yanked at '11th hour' over security concerns." First, I need to make it clear and professional. "Yanked" is a bit informal, so maybe "canceled" or "postponed" would be better. The phrase "11th hour" could be rephrased to "last-minute" to sound more formal. Also, the security concerns are the main reason, so I should state that clearly. Need to avoid any specific terms like "UMVA" or "Breaking." Let me check the key elements: who (Harry and Meghan), what (UK visit cancellation), when (last-minute), why (security concerns). Let me piece that together concisely. Maybe start with "Last-Minute Cancellation of Harry and Meghan's UK Visit Due to Security Concerns." Wait, the user said not to mention any platform-specific branding, but I didn't include that. Let me make sure it's concise and engaging. Perhaps "Security Concerns Prompt Last-Minute Cancellation of Harry and Meghan's UK Visit." That sounds good. It's clear, professional, and includes the key details without sensationalism. Let me double-check the requirements. Yes, only one headline, no options, no lists, no quotes. Looks good.