Crash on Play or Packaged Project

building debug editor and then playing in editor throws this error

I’m not sure what changes i did that could of caused this.
Our unreal project will not play if World Terrain or a 3D tile is present and will crash at this point in the program. If i make a new level and set up a basic cesium environment (sunlight, pawn, world terrain) it will crash on play.

Hi, what version of Ceisum for Unreal are you using? Is it installed in your Engine plugins directory via the Epic Marketplace? Or something else?

Cesium for Unreal v1.5.0 installed into engine plugins directory via epic market place.
Unreal Engine 4.26.2
The project will not crash if I remove any 3d-tiles.
The project works on 2 computers and fails on 2 computers.
There are no issues in a new unreal project.

Looking at your screenshot a little closer, I can see that your viewport size is 0x0 pixels. That’s likely causing an exception when creating the frustum, which in some configurations of UE will cause immediate program termination (because exceptions are disabled).

v1.5.0 gained support for multiple viewports, so most likely it’s too eagerly finding a dodgy camera/viewport that it previously would have ignored. You can confirm this by downgrading to v1.4.1 and see if it fixes the problem. Old releases are available here:

Just remove your current version via the Epic Marketplace, and then extract the v1.4.1 ZIP file to:
C:\Program Files\Epic Games\UE_4.26\Engine\Plugins\Marketplace

It’s probably also worth taking a look at your level to see if you have any unused cameras or collapsed viewports or something that you can simple remove.

Actually, we may have a fix for this issue. Can you try downloading and installing (as described above) the build below and let us know if it helps:


Sure, i did what you suggested before btw and it’s working again.

So the application doesn’t crash anymore but this artifact comes up now.
This was in play in editor.

Play in standalone would not crash, but no world tiles were showing up and the globe was just blank blue atmosphere.

That screenshot is v1.4.1, right? Can I bug you to try the dev build linked above?

Sorry for the confusion, That screen shot is from the dev plugin you shared, and so is this one. By playing in the editor viewport, it’s not set to simulation either.

In standalone play it behaves differently

Hmm interesting, I can’t quite explain that. Any chance you could share a cut-down project with us that exhibits the problem, so that we can debug?

Hello @Darb_Dude,

We are having some difficulty reproducing your issue, but the fact that the above dev build prevented the crash suggests that the plugin is picking up an invalid stereoscopic rendering device and perhaps incorrectly choosing the stereoscopic rendering path.

In the interest of debugging further, some questions: Is it possible that you have a VR device plugged in, even if you are not actively using it? Otherwise, do you have any VR software like SteamVR that opens alongside Unreal, even in the absence of a plugged-in headset?

Either way, let us know if this updated dev build fixes the issue:

Hopefully it helps!
-Nithin Pranesh

Here’s a cut-down project.

I was messing around with hololens2 before but I thought I disabled the WindowsMixedReality plugin.
If I disable it then it no longer crashes.
There are no hmd devices connected but the WindowsMixedReality is enabled.
Thanks guys! let me know if you need anything else.

Ah I see, I’m finally able to reproduce the issue by enabling the Microsoft Windows Mixed Reality plugin! I was able to reproduce the crash using 1.5.0, and using the first dev build I was able to see all the missing tiles as you described. The latest dev build linked above seems to fix both issues for me. Can I bother you to try out that latest build in my last comment? I’m reasonably confident the issue should be resolved now, but let me know if it doesn’t fix the issue for you.

Nithin Pranesh

Hey I swapped out the plugin with the last build you shared and it did appear to prevent the application from crashing, and draw the world correctly. It seems to be working as before.

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Great, thanks for letting us know! That fix is included in v1.5.1 which is now available from the Epic Marketplace.