Code inspection: Creating a managed type is not supported

This inspection reports new expressions that create managed types inside code compiled by the Burst compiler.

Burst targets a high-performance, restricted subset of C# and only supports unmanaged, Burst-compatible data. Creating managed objects such as object, List<T>, exceptions, or other reference types inside Burst-compiled code is not supported, as it requires managed heap allocation and garbage collection.

Example

In this example, the new List<int>() expression is used inside the Execute method of a Burst-compiled job. This is not supported and will be flagged.

                using System.Collections.Generic;
                using Unity.Burst;
                using Unity.Jobs;

                [BurstCompile]
                public struct ExampleJob : IJob
                {
                    public void Execute()
                    {
                        // Reported: Creating managed types is not supported in Burst
                        var values = new List<int>();
                    }
                }
            

                using Unity.Burst;
                using Unity.Collections;
                using Unity.Jobs;

                [BurstCompile]
                public struct ExampleJob : IJob
                {
                    public NativeArray<int> values;

                    public void Execute()
                    {
                        // Use Burst-compatible value types or native containers
                        var first = values[0];
                    }
                }
            

Quick-fix

This inspection does not provide a dedicated quick-fix. Fix it manually by removing the managed allocation and replacing it with Burst-compatible data, such as instance fields, job data, or a supported native container.

26 March 2026