Null exception in _unity_self

Unity Engine
1

I’m getting this strange null exception, not really sure if it’s a 2019.3 issue, a Linux issue, or an HDRP issue.

This is caused by the code:

        if (myCamera != null)
        {
            myCamera.RemoveAllCommandBuffers();
        }

Edit:
Seems to have been fixed by also checking if myCamera.commandBufferCount > 0 before removing command buffers

2

I was wrong, that didn’t fix it. I’m still getting that null exception in _unity_self whenever I remove command buffers

3

Could you please submit a bug report with a minimal reproduction project?

4

Looking at the stacktrace, it seems like you actually have a null CommandBuffer attached to the camera - the null isn’t referring to the camera variable.

Sorry the error message isn’t very helpful - a bug report would still be useful to help us improve this. Not sure how/why a null CommandBuffer would be attached to the camera, or even if that’s something Unity should let you do.

5

It is only happening when a Scriptable Object(SO) is visible in the Inspector. If I do not have a SO visible in Inspector, I do not have that issue.

2 Likes
6

Yes, I get the same error when a gameobject’s script containing an array of SO’s is displayed in the inspector. I changed it to a List instead of an array and that seems to have solved the problem.

7

Am on Unity 2022.3.34 (latest) and got this error too. Thought it was random but then realised that it was dependant on what item I had selected before I hit play.
Tracked it down to an exposed class in the component on the selected object

public StateHistory history = new();

The StateHistory class has a [Serializable] at the start so I can see the history in the inspector, but if I remove this Serializable attribute the crash at the start goes away. Seems to be an inspector issue with this kind of class.

[Serializable] // Remove this and the error goes away (and this history is not visible in the inspector
public class StateHistory
{
    public const int historyLength = 10;
    [Serializable]
    public struct HistoryEntry
    {
        public string state;
        public float time;
    }

    public List<HistoryEntry> history = new();

    public void AddToHistory(string state)
    {
        if (history == null) history = new();

        history.Insert(0, new HistoryEntry() { state = state, time = Time.time });
        if (history.Count > historyLength)
        {
            history.RemoveAt(history.Count-1);
        }
    }
}