Unknown. It happens randomly.
This bug was already reported here, but was marked as resolved and closed, although it is still happening again. The post should be revisited again for all the details.
One of the comments of the topic mentioned that it happens when you weld a tool when the character spawns. However, it seems more general than that, as it has also happened with characters with no tools in my game according to the community.
Many people in my group are complaining about the bug, as the context of my game requires to see killers, who are sometimes invisible.
The game is here: Survive and Kill the Killers in Area 51 !!! - Roblox
All characters’ body parts should load and be visible.
Sometimes, some, or all body parts are invisible. This visual bug is critical in the context of my game, as the characters for who it is happening are killers, and they can therefore kill the players without even being visible.
Here are a few examples grabbed from the community:
Fully invisible (worst case):
Here, killers are breaking the planks without being visible:
In addition, some people in the community told me the bug also happens in some other games. Here are more examples:
Issue Area: Engine
Issue Type: Display
Impact: Very High
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