Before you press Play
The asset checks its generated Runtime Data before Play. If your placements or settings changed, it may ask to prepare that data. Let preparation finish; an unchanged scene can reuse its previous data next time.
Moving through a large world
Streaming loads vegetation near the camera and releases distant render regions. Your World Data stays intact. If you supply a custom runtime region provider, keep its source available for the regions the camera can reach.
After you stop
The Editor restores its vegetation view after Play. Runtime placements are discarded unless you saved them. Open Keep Runtime Edits and enable Save on Stop, or use Save Runtime Edits Now, to keep a placement snapshot. Saved placements become the source for the next preparation.