Random FPS Drops Linked to Chat CoreScript

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1

I’m trying to figure out why the project I’m working on starts getting random FPS lag spikes after playing for a while.

After around 1–2 hours of gameplay, the FPS suddenly drops in big spikes. This usually happens more often after the character dies a few times.

I checked with MicroProfiler, and every single time the spike is caused by:
Script.SchedulerHostConfig.default newindex_TextStrokeTransparency

It seems to come from the CoreScript of the chat system.

Right now, I only have one MicroProfiler dump in HTML format. The main thing to look at is frame 18, where the TextStrokeTransparency shows up during the lag.

I went through my scripts to check for bad loops or objects not being cleaned up, but couldn’t find anything on my end. It always points back to the chat CoreScript.

Every spike is the same: it’s always related to TextStrokeTransparency.

At this point, I’m not sure if this is something I can fix on my side, or if it’s a Roblox issue that should be reported.

HTML of the MicroProfiler dump:
microprofile-20250928-005814.zip (8.0 MB)

Some screenshots of the MicroProfiler:

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image1869×922 140 KB

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image1640×912 90.5 KB

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image1687×213 98.7 KB

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image1109×203 68.4 KB

3 Likes
2

Agreed. My earlier patch was heavy-handed. Here’s a clean, safe fix that avoids _G, avoids poking CoreGui, and removes the TextStrokeTransparency hot-path entirely.

if script:GetAttribute("init") then return end
script:SetAttribute("init", true)

local TextChatService = game:GetService("TextChatService")
if TextChatService.ChatVersion ~= Enum.ChatVersion.TextChatService then return end

local function trySet(o, prop, v)
	if o and o[prop] ~= nil then
		local ok = pcall(function() o[prop] = v end)
		return ok
	end
end

local win = TextChatService:WaitForChild("ChatWindowConfiguration")
local bub = TextChatService:FindFirstChild("BubbleChatConfiguration")

-- turn off stroke; no CoreGui traversal
trySet(win, "TextStrokeTransparency", 1)
trySet(bub, "TextStrokeTransparency", 1)
1 Like
3

That is some ridiculously cursed code

First, write to a random _G index (I guess it’s a game wise debounce variable?)
Then, tries to use :GetService("CoreGui"), which isn’t a valid service, from what I’ve tested
Even if you do game.CoreGui, roblox doesn’t let you, and returns nil instead

Then tries iterating over every object inside of CoreGui to set the TextStrokeTransparency to 1 (including stuff unrelated to the chat)

Then tries to also iterate over elements in RobloxGui (still not accessible cuz inside of CoreGui), to set a limit of 600 visible labels, but those labels are… Random labels from random guis (like the backpack, AvatarContextMenu, VehicleHudFrame, …)

1 Like