Save Map Under Different Name Keeps Crashing, Not with same name

hey,

when i try to save my map under a different name, my editor keeps crashing, if i save it under the same name, it don’t crash … :confused:

i have this since i builded the lighting.
My map is a bit big, but should not be a problem i think with ue4 … i’m trying to build a landscape with many water with all kind of islands, have not made water yet, only the landscapes without anything build on it yet, and still it takes a huge amount of memory.

also building the lighting takes very long but most important is :
i have 32 GB RAM and it consumes everything very quickly and results as hangin/crashing/ and os unstability or complete os crash.

My Specs :
Os : Win 7 Ultimate x64
CPU : FX 8350 4.0 Ghz up to 5.3 Ghz (still takes time at higher clocks to build.)
GPU : Asus Strix GTX 970 4 GB
RAM : 32 GB
SSD : 250 gb & 1 TB
HDD : not relevant as i use my SSD.

i tryed to use dimmdrive ram disk but it’s not performing that much faster and i can’t use it because my RAM usage is very high.

i Deleted the “xxxMapNamexxx_LightBuild.umap” file and now i can save again under different names … but i lost the lightsbuild … anyway, seems there is something wrong with building the lighting since it takes up to 3-4 hours to build or i’m doing something wrong.
and mostely it won’t begin to build since it takes out my 32 gb ram.