deserializeBufferedPackets causes a significant performance drop

[Squidacy (Squid)]

I am not sure why this is happening, but whenever deserializeBufferedPackets is handled on RBX Worker A it seems to be blocking the main thread instead of running in the background. This causes huge frame spikes, some lasting up to 5 seconds

System Info
OS: Windows 11
CPU: Intel(R) Core™ i7-14650HX
GPU: NVIDIA GeForce RTX 5070
RAM: 32GB

Expected behavior

deserializeBufferedPackets should run asynchronously without affecting the main thread.

A private message is associated with this bug report

[Dominilk001 (Dominilk)]

geting same thing, terible lag spikes

[watamelnKalashnikov]

Getting reports of the same issue for our players

[olivier_primeau (ZiguezonZinzon)]

Same issue here. Getting terrible lag spikes. Thought I was going crazy.

[jnprge (Interesting)]

same thing happening on:
RIVALS

Darkest Hours (not my footage)

[NodeSupport (Node)]

Can confirm this is an issue;

Seeing really bad hang times and frame drops from this.

[jnprge (Interesting)]

seems to only really happen with games that require constant usage of (Unreliable)RemoteEvents; games that don’t use it (e.g. Survive the Disasters 2) aren’t really affected by this bug use a lot of network?

[NodeSupport (Node)]

We don’t use UnreliableRemoteEvents, this isn’t true.

[BIGHEAD_RIPOFF]

Experiencing the same issue. Really annoying as I have to reinstall Roblox to fix it but several hours later it reappears and it quite literally freezes my entire client (completely, can’t do anything at all) at some points making me have to use task manager to kill the client.

[jnprge (Interesting)]

ah so its just a global roblox issue, nvm

[tinypony_25 (Tiny)]

Does roblox know about this yet

[Crab_Wrangler]

This is occurring to me on a very non-intensive game, would appreciate staff looking into this!

[miracleayz]

Ohh so Roblox just broke my game. Cool!

[Pikachuinfinit]

save jujustu shenanigans Squidacy

[TheGamer101]

Thanks for the detailed reports and microprofiler screenshots, and sorry for the inconvenience caused here.

We are actively investigating this issue, and we currently are exploring if this was caused by a regression in some low level replication or task scheduling logic in the latest engine release.

We are working on verifying this theory and pinning down exactly what change caused this, and we will be rolling back the release to address the issue.

The rollback should be completed within the next hour or so, I will update the thread again when that’s been completed.

[TheGamer101]

The fix has just been released, please let us know if you are still encountering this issue.

[olivier_primeau (ZiguezonZinzon)]

Game is no longer freezing, however significant frame drops are still occuring on my end.

[TheGamer101]

Telemetry on our end is showing recovery. Do you have a microprofiler dump so we can check that it’s the same issue? Also, can you let me know your Roblox client version? The version is shown in-game at the bottom of the screen when you open Help in the menu, or in the About section of the More page in the app.

[olivier_primeau (ZiguezonZinzon)]

d70631

[TheGamer101]

Looks like this is a separate issue, would you mind filing another bug report in a new thread with more information such as device, place, logs and a full micro profile dump? Thanks.