UE 5.3 crash Assertion failed: Desc.GetSize() > 0 Creating buffer 'CapsuleTileIntersectionCountsBuffer' is zero bytes in size.

[Arodi007 (Pixiebell Games 💼)]

It seem to be related to your Capsule shadow for your character bp, try to modify it size or even disable it.
Ref: Capsule Shadows Overview in Unreal Engine | Unreal Engine 5.3 Documentation