StaticBatchingUtility.Combine crash on device

I had a prefab about 1700 draw call. The prefab is instatiated at run time and it is not inside a scene so i use static batching utility combine to batch the draw call. While in editor i have 43 drawcall and about 1600 batched. On device i have a crash and the call stack says render get shared material…

  1. when a prefab is not inside a scene the only way to batch is to use staticabatchingutility combine, am i right?
  2. if a prefab is inside a scene the only way it is batched is when i set mesh read and write enabled, is this right?
  3. there are any other way to batch or someone has the solution to my crash?

I tried to reduce the draw call number to 2 and works. Too many draw calls? Is there a limit to static batching?

solved i had a gameobject without a material. It should be better Unity outputs an error message