While trying to make a winter survival map I first created my ‘persistent’ main level. With that open, I opened the ‘Levels’ window and from that I tried to create a new level…
The issue:
While trying to save this new level, Unreal Engine goes slowly from its initial 3 GB memory used, up to about 12 GB resulting in 95% of my systems 16 GB being used.
After some time, the memory used by unreal drops to about 6 GB, however the system is still using 95% of its total memory. (the 6 GB dropped memory is simply considered modified memory that has to be cached before being freed)
Slowly unreal gets back up to the 12 GB, repeating the process until I finally terminate it.
How to avoid this:
When I finally got tired of trying this approach, I simply created another level in my maps folder by right clicking… then from the persistent level, I opened the ‘Levels’ window and added it as an existing level… That worked flawlessly and saved within a few seconds!
I apologize if this is a known bug or by design