Reproduction Steps
Using the PhysicsService:SetPartCollisionGroup method, you can cause it to error by attempting to set a part’s CollisionGroup to the Default group, giving you this error.
This is a bug, as every other method of setting a part’s collision group to Default works, such as setting the CollisionGroup or CollisionGroupID property of the part directly. This is also a very recent issue, as I have been setting parts’ collision groups to Default using this method for a couple of years and only ran into it today.
Below is an example file, showing off that trying to set the Collision Group using the method causes an error. The other two parts included side-by-side show off the intended behavior by setting the CollsionGroup or CollisionGroupId property to Default.
CollisionGroupErrorExample.rbxl (35.9 KB)
Expected Behavior
I expect the CollsionGroup of the part to be set to Default using the PhysicsService:SetPartCollisionGroup method.
Actual Behavior
It gives an error stating that you cannot use or change the Default collision group. This stops the part from being set to Default.
Workaround
Setting the part’s CollisionGroup property to “Default” allows me to workaround this.
Issue Area: Engine
Issue Type: Other
Impact: Moderate
Frequency: Very Rarely
Date First Experienced: 2022-09-13 07:09:00 (-04:00)