Parts glitching / flinging since last update

Bug Reports Engine Bugs
#1

Reproduction Steps
Reproducing this bug has proven difficult since it does not occur for every server nor every player (if in studio). For some players, parts will randomly fling out of bounds / glitch out and simply disappear. I cannot personally reproduce this problem in studio, only in affected live
servers.

I have no idea why this bug occurs, but it’s only started occuring since yesterday’s release notes and no code was changed from there. Noteworthy to mention systems like this have began to break in more than one of our games.

Expected Behavior
I expect parts to function as normal.

Actual Behavior
https://cdn.discordapp.com/attachments/600724303474065427/862757962744332348/2021-07-08_19-11-45.mp4 (both of these parts are anchored, and a TweenService change of CFrame is applied to make them go together; however, this does not occur and instead they completely break - when I test in studio, they act perfectly normal and do not glitch out)
https://gyazo.com/50c530c214b4166ebe0081ced76506cd (note that for this example, a ragdoll system is applied, and joints disappeared randomly)
image (tool dropping system, parts seem to disappear when the new dropped gun model is created)

Issue Area: Engine
Issue Type: Other
Impact: High
Frequency: Often
Date First Experienced: 2021-07-07 00:07:00 (+00:00)

8 Likes
#2

I think this update affected me in a different way, but I think both of us are relatively negatively affected.

My issue is that ever since yesterday, my game, that uses destructive large maps, experiences timeout errors when trying to load in bigger maps. This has NEVER happened before, and it’s to do with the joint welding process of the parts.

My game is completely broken from this and has been closed since 7 PM yesterday. While we don’t have the same issue exactly, I’m pretty sure this physics update affected both of us negatively. I really hope a staffer can look into this problem.

4 Likes
#3

Could this please be looked into? This is breaking key components of my game and breaking systems on others. This is something that should receive a high priority imo, it’s been two days and the damage is still manifesting.

2 Likes
#4

Thanks for the report! Can you provide a game where you encounter this problem?

2 Likes
#5

Yes! Our open world game Glacier has been experiencing a lot of issues related to this which has broken some key systems, such as dropping, vehicle spawning or drones. (The game itself has a bit of a learning curve so new players can’t really experience these issues right away, but generally anything involving welds created / parented to Workspace at run time seems to experience the same problems)
Cloning a tool’s content into a Model, and parenting said Model to workspace for example, should be able to reproduce this problem.

#6

In that case can you provide another game? One in wich I can see the bug more easily?

1 Like
#7

yes similiar thing is happening in my game, with metro boogies just disappering randomly when the train gets anchored. That bug started happening at around same time as these. I was personally able to “fix it” with removing auto anchoring from the vehicle. The boogie is attached with a HingeConstraint and a weld to the body of the train.

1 Like