Typescript version of Away3d throws exception when tried to remove a child.
The exception is happening at Scene.ts

displayObject._iAssignedPartition is null

This happened to me, too. After lots of debugger stepping I think the reason for the crash is that when removing a child, its “_pImplicitPartition” is first set to null and later on the “iUnregisterEntity” function crashes, if the “_explicitPartition” is not set on the child

My fix for this is to insert this line:

here into the Away3D code:

TYPESCRIPT: awayjs-core-ts-master/src/away/core/base/DisplayObject.ts
BEFORE line 1964 (“this._pUpdateImplicitPartition(null);”)

[removed] awayjs-core.next.js
BEFORE line 10075 (“this._pUpdateImplicitPartition(null);”)

Maybe you could try that and tell me if it it fixes your crahes also