Hi @Goldenfiz!
Yeah, running out of memory is a very common issue with large open worlds, and not always the easiest to diagnose. Is your level empty other than the landscape?
Firstly, I would check your HLODs and make sure your landscapes are excluded from any HLOD layers, as they are not supported and are a common cause of memory crashes.
Here’s some documentation on World Partition HLODs and how to use them properly:
https://dev.epicgames.com/documentation/en-us/unreal-engine/world-partition---hierarchical-level-of-detail-in-unreal-engine?application_version=5.1