RobloxPlayer (Windows) hard crashes on teleport (Access Violation)

Bug Reports Engine Bugs
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1

We are currently developing a game that is private - but during our internal play tests most people crash most of the time when trying to teleport.

The game is setup so the group is teleported to the same PlaceId but a reserved server.

What is common between all people is that they use Roblox Player on Windows, but the hardware setup is different.

Exception: c000005 (Access Violation from a near-null address)

All crashes:

  • Same faulting instructions
  • Attempt to read from near-zero addresses (0xce8 and 0x2020)
  • WinDbg label: NULL_CLASS_PTR_READ_AVRF

Crash seems to happen at 0x2bad92c every time.

The LUAU code we use to teleport is not that complex:

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Side note: The forum seems to not allow pasting text from the outside on Firefox anymore…

Expected behavior

I expect the teleport to happen without the C++ layer crashing the application.

A private message is associated with this bug report

2 Likes
2

Our guesstime is that it is a 50/50 chance for a crash, it also seems to happen when playing solo.

The strange thing is that I personally have not experienced a single crash.

3

I added a print on OnPlayerAdded - the players crashing never print anything. So they fail to connect to the server.

4

We just tested another game that has a similar teleport feature and that game does not trigger the crash when teleporting for the same players that crash in the topic game.

So it is something subtle going on.

5

OK - we have narrowed it down slightly.

It seems to be related to that we fire a RemoteEvent to server → clients just before we trigger Teleport and this causes the client to crash. Removing the call to fireTeleportEvent() stops the client from crashing.

Might be something further down the chain, will investigate further.

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