Your computer is low on memory, how to fix?

I recently made a VR game in the Unreal Engine 4.12.5.
After about 1 hour after booting up the game it crashes with this error:

Both the RAM and the VRAM can’t handle the game. And it crashes after a while with about the same message.

Specs:
16 gb RAM
Nvidia GTX 1080 8 gb VRAM
Intel Core i7 6700K

I’m facing the same problem and haven’t been able to find a solution yet.

click start .
then type advanced system settings
In performance press settings
go to Advanced tab
in Virtual memory click change
select C: drive and check System managed size
press set button
click ok…
then restart

I fixed it with deleting a light in my particle. Everytime the particle played the vram increased.