I have previously trying to burst compile a job which contains ecb.SetSharedComponentData but burst debugger error says that function contains the use of `null` and not allowed to burst compile. Then today I use only `SetComponentData` and `AddComponentData`. It then says either you are setting a non existent component data (haven't add yet but try to set) or you cannot add 2 of the same component. (use add again instead of set) The Burst Debugger did not output compilation error this time. I don't know how it turns out that way. The function is going haywire and I guess it order the command in the buffer randomly, because it works correctly without [BurstCompile]. (I can turn on and off "Enable Burst Compilation" to reliably produce error and make the error disappear) So is this a known limitation that Burst will not work with any kind of Entity Command Buffer? I have tried both IJob/IParallelForJob and EntityCommandBuffer/EntityCommandBuffer.Concurrent , same result.