You’re in Sapienza. You’ve spent twenty minutes meticulously clearing out the biolab, dodging that one annoying female enforcer, and finally, you’ve got the Plague Doctor outfit on. You reach for the katana in the attic—the one that’s been sitting there since the 2016 release—and suddenly, the screen flashes like a strobe light at a bad rave. Or worse, the mission just fails instantly.
Welcome to the Eccleston Illumination katana bug.
Honestly, if you've played through the World of Assassination trilogy long enough, you know that some escalations are just "legacy jank" wrapped in a new engine. The Eccleston Illumination is the poster child for this. It’s a five-level escalation in Italy that demands very specific, very weird kills. But between the lighting engine updates in Hitman 3 and the way the game handles specific item IDs, this mission has become a minefield for players just trying to get that sweet mastery XP.
What is the Eccleston Illumination Katana Bug?
Basically, there isn't just one bug; it’s a cluster of three different issues that people often lump together because they all happen during Level 5 of this specific escalation.
First, there’s the visual "illumination" glitch. This happens mostly to PC players on newer hardware. Because the Hitman engine (Glacier) underwent massive lighting overhauls for the 2021 release, some of the older "filters" used in escalations don't play nice with modern Ray Tracing or HDR settings. When you equip the katana while wearing the Plague Doctor suit, the game tries to trigger a specific visual state. Instead, for many, it triggers a blinding flicker.
Then you’ve got the "Item Identity" fail. This is the one that makes people rage-quit. In Level 5, the "Katana Plague" complication requires you to kill targets with a katana while dressed as the Plague Doctor.
Here’s the kicker: the game often doesn't recognize "any" katana. If you bring your own unlocked Masamune or White Katana in a briefcase? Instant fail. The game’s code for this legacy mission is hard-coded to the specific Katana object found in the Caruso attic.
"I threw the Masamune at a target's head and the 'Mission Failed' screen jump-scared me before the body even hit the floor." — This is a sentiment shared by dozens of frustrated players on the Hitman forums.
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The Plague Doctor Disguise Dilemma
It gets weirder. You’d think the Plague Doctor is the Plague Doctor, right?
Nope.
If you use the unlockable Plague Doctor suit (the one you get for completing the "Street Art" or similar challenges), the mission might fail to register the kill as valid. The escalation was built when the only way to get that suit was to find it in the villa's observatory. Using the "wrong" version of the same outfit is a classic case of the game's old logic clashing with the newer "World of Assassination" inventory system.
How to Fix the Flickering and the Fails
If you’re staring at a flickering screen or a "Mission Failed" screen for the tenth time, you’ve gotta change your strategy. Forget about your fancy unlocks.
- Use the Map’s Assets: Don't bring a katana in your loadout. You must go to the attic and pick up the one leaning against the wall near the safe.
- The "In-World" Suit: Don't start the mission wearing the Plague Doctor suit if you have it unlocked. Go to the observatory in the mansion and put on the one that's actually on the mannequin.
- Lighting Fix: If your screen is pulsing black or flickering, go into your graphics settings and turn off Ray Tracing Reflections and HDR. The legacy bloom effects in Sapienza are notoriously broken in the 3.0 version of the engine. Some players also find that toggling "V-Sync" or switching from DirectX 12 to a different window mode stops the seizure-inducing flashes.
Why IO Interactive Hasn't Fully Patched It
Look, IOI is great at fixing game-breaking exploits (like the recent "Le Chiffre banana peel" bug in the 2025 Banker update), but legacy escalations from 2016 are low on the priority list. These missions have "spaghetti code" roots. Changing the item ID for the katana in this one mission might accidentally break the katana in a hundred other contracts.
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It's annoying, sure. But in a way, it’s a rite of passage. Figuring out that you can’t use the Masamune is part of the "Hitman experience."
If the lighting is still driving you crazy, try the "VR Blinders" trick. Sometimes the game thinks you're in VR mode (even if you aren't) and applies a vignette that causes that weird pulsing. Checking your PipelineCache.bin file and clearing it can sometimes reset these weird visual states.
Your next step is simple: Boot up Sapienza, head straight for the observatory for the "real" suit, then hit the attic for the "real" sword. Leave your smuggled gear in the ICA safehouse; it’s only going to get you a "Mission Failed" screen. Once you've cleared the level using the map-spawned items, you'll likely find the bug disappears entirely.