Part's Disappearing + Lighting Bugs

Bug Reports Engine Bugs
#1

So, for some reason in my game, there’s some strange bugs relating to collision. When I climb a ladder into a brick above my head, my character disappears, and a massive shadow appears. This also happens when I run into things or sometimes even just fall on things. I use the default ROBLOX character, turned invisible, with a custom model welded to them that’s used with animation and collision.

When I climb a ladder:
https://i.gyazo.com/75db016f1107521c210a7c4ba9e62151.mp4

When I hit my head on a wall (the body leans forward when you look up/down with the camera)
https://i.gyazo.com/81d6acaeddae4f17c196ac89db31abd9.mp4

#2

A repro showing the SelectionBoxes of the character when it’s happening would probably really help.

#3

For the ladder climbing one it’s the default character, no extra collision. I’ll get a collisionbox for the other tomorrow.

#4

That looks a lot like the behavior you get when two parts with a frictionweight of 0 collide. Could that be the problem?

#5

For the ladder climbing one it’s the default character, no changes to frictionweight. For the other I made sure to set frictionweight to 1 after I read about the frictionweight 0 bug, but it still happens.