Editor: ArrayEditor leads to crash

## Description

ArrayEditor leads to crash

## Prerequisites

Open Editor and project. 

## Steps to Reproduce

1. Create and select MeshRender Actor
2. Remove all materials using [-]
3. Add new material using [+]

### Expected behavior:

3. Material added

### Actual behavior:

3. Application crashed

### Reproducibility:

100%

## Versions

2025.2

## Additional Information

n/a
