InvalidOperationException: Adding/removing components or changing position/rotation/velocity...

InvalidOperationException: Adding/removing components or changing position/rotation/velocity/collider ECS data on dynamic entities during physics step.

I understand why this is happening in terms of code, this exception is throw when I use FixedStepSimulation update group and manipulate PhysicsVelocity or Translation, but what if I need it? What am I doing wrong?

Here is code triggering it:

Code (CSharp):

1. [UpdateInGroup(typeof(FixedStepSimulationSystemGroup))]
2. public class PhysicsMovementSystem : SystemBase
3. {
4.     protected override void OnUpdate()
5.     {
6.         float deltaTime = Time.DeltaTime;
7.  
8.         Entities.ForEach((
9.             ref PhysicsVelocity velocity, in MoveData moveData, in GravityData gravityData) =>
10.         {
11.             var multiplier = moveData.Speed * deltaTime;
12.             velocity.Linear.x = moveData.X * multiplier;
13.             velocity.Linear.z = moveData.Y * multiplier;
14.             velocity.Linear.y = -gravityData.Strength;
15.         }).Schedule();
16.     }
17. }

 

I feel completely stupid

Code (CSharp):

1. [UpdateInGroup(typeof(FixedStepSimulationSystemGroup), OrderLast = true)]