Bug Loading Entity Scene failed because the entity header file couldn't be resolved.

Using Unity 2022.2.0b16 and entities 1.0.0-exp12

Basically every time I change some c# code, unity recompiles, it happens
Restarting editor and clearing entities cache in preference doesn't help.

You can see which subscene is affected by toggling the subscene
The only fix I found is open the subscene, move all object out of subscene, then move it back it and save it.
Doesn't work all the time though, something even if you delete every gameobject in the subscene so that you leave it empty, it still shows that error when toggling the subscene.

The thing is after the above "fix" is done, I check the git commit, nothing has change, not a single line in the subscene file, or the meta file. I guess some file has gone corrupted somewhere in the Library folder.
Deleting the library folder will of course fix it as well.

Opening the asset import log like the error suggested show this:

Code (csharp):

1.  
2. Exception thrown during SubScene import: System.NullReferenceException: Object reference not set to an instance of an object
3.   at Unity.Entities.TypeManager.CallManagedEquals (System.Void* left, System.Void* right, Unity.Entities.TypeIndex typeIndex, System.Boolean& wasequal, System.Boolean& didwrite) [0x00004] in C:\RenderTest\Library\PackageCache\com.unity.entities@1.0.0-exp.12\Unity.Entities\Types\TypeManager.cs:1777
4.   at Unity.Entities.TypeManager.EqualsWithBurst (System.Void* left, System.Void* right, Unity.Entities.TypeIndex typeIndex) [0x00019] in C:\RenderTest\Library\PackageCache\com.unity.entities@1.0.0-exp.12\Unity.Entities\Types\TypeManager.cs:1764
5.   at Unity.Entities.EntityComponentStore.FindSharedComponentIndex (Unity.Entities.TypeIndex typeIndex, System.Int32 hashCode, System.Void* newData, System.Void* defaultValue, Unity.Collections.LowLevel.Unsafe.UnsafeList`1[Unity.Entities.EntityComponentStore+SharedComponentInfo]*& infos, Unity.Entities.ComponentTypeList*& components) [0x0001b] in C:\RenderTest\Library\PackageCache\com.unity.entities@1.0.0-exp.12\Unity.Entities\EntityComponentStore.cs:1485

Search on the forum:
https://forum.unity.com/threads/sol...ile-couldnt-be-resolved.1018339/#post-8563187
https://forum.unity.com/threads/1-0...ile-couldnt-be-resolved.1356305/#post-8566238

 

This bug seems to no longer occur to me with Entities-1.0.0-pre.15 for me.

I had it all the time with exp.12, workaround there was clearing Entity Cache in Preferences and then restarting unity. Sometimes.

 

Just noticed new entities version released today, will try that.

 

Still happen in Entities-1.0.0-pre.15 with 2022.2.0f1
Will try to find a way to reproduce

 

Anyone facing the Loading Entity Scene failed because the entity header file couldn't be resolved issue:

I've figured out that this issue is rarely related to the problem with the SubScene itself, but instead is cause by the Exception thrown by Burst compilation during the SubScene import. To try and identify the source of the real problem you can:
1. Disable the SubScene in the Hierarchy and run the PlayMode - sometimes it shows the bugs and exceptions that are not show with the SubScene being turned on (such as
GetSingleton() requires that exactly one entity exists that matches this query, but there are {0}
)


2. After getting the Loading Entity Scene failed because the entity header file couldn't be resolved error, go to /Logs folder of your project and open the "AssetImportWorker[0-N].log file.


Type in the "Exception" in the search - you will probably be able to find something like this:



In my case, the compilation exception was caused by incorrectly managing native collections. In yours - it might be smth else. Anyway, you can comment out the problematic code and try building again to check if it indeed is the source of the problem. Hope it helps!