Steps to reproduce:

1. Open attached project
2. Open and play 'Tower_AI' scene
3. Open scene view and move one of the cubes closer to the tower
4. Notice the tower shoots a projectile with a Trail Renderer and when it hits the cube, the projectile instantiates a simple explosion
5. Wait for a couple of shots, editor will crash

Notes:
Instantiating the explosion from the same bullet object without a trail renderer, does not crash the editor.
Instantiating any other object also does not crash the editor.