Build does not load Entities

Entity Component System (ECS)
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1

Hi,

I have been working on a game for few weeks with the new ECS 1.0.x, and now I am ready build it.
However when I run a build nothing in the sub scene shows up, only things in the main scene.
After not finding many answers, I made a completely fresh project and just created a sub scene with a cube in it.
These are the errors I get when running it in a build
Top level scope allocation is permitted only on the main thread.
and

NullReferenceException: Object reference not set to an instance of an object.```

Everything works fine in the editor.

Any help would be very welcome, I have included the player log and the fresh project I put together.

[9180293--1278695--Player.txt|attachment](upload://aq3A1iWAMN6tfg2dZtrKrX06HAZ.txt) (29.2 KB)
[9180293--1278698--ECSTest (1).zip|attachment](upload://gOawTvQkPNUhoOXLT18LG2lm0Ac.zip) (75.1 KB)
2

So I am still investigating, but seems to be an issue with URP. I made the same simple project in HDRP and it worked. Testing a bit more now with a simple system.

3

This has been fixed for 2022.3.6
https://unity.com/releases/editor/whats-new/2022.3.6
9190958--1280921--upload_2023-8-3_16-17-56.png

4

So having spent more time on this, it is not URP vs HDRP, but actually Unity 2023.1.0 not allowing sub scenes to load correctly. Hopefully will be fixed soon.

5

Just switch to Unity LTS version. You are working on “unstable” release, which may contain many incompatibilities.