Out of curiosity, what is your computer's CPU/Graphics Card/VRAM/System Ram specifications? Do they meet the minimum required specifications for this game? Not being mean, merely asking, as I make maps myself, but had 0 issues running this on a 'modest gaming computer' that's dated a few years (it's over 4 years old with a 2 year old Radeon RX 480 and the RAM is maxed at 32gb and stuffed with SSD's for said map-making). Turn off reflections to help GPU and CPU (lessens draw calls = helps CPU) Turn off shadows (helps CPU substantially) or set to player only Turn off SSAO (helps GPU and may lower draw calls - not sure but it helps) Make sure you don't exceed the graphics memory of your computer - this is separate from system memory (even though it may be a portion of the system memory on some lower-end machines). If you exceed this, things will be forced to be stored in system memory, and things slow down exponentially. I'm talking from 40~50fps to 10fps or less. Don't do that. Lower the graphics texture detail here to help, if you're on integrated graphics, please use LOW settings as even on medium my maps for example can gobble up 1~2gb with zero issue. I am not the author of this map, but I am familiar with this map, and I've been mapping several years now (about 3 years, and modding games for about 25 years). I tend to infest the forums on a regular basis with the side-effect of book-like posts (I also sell reading glasses - kidding). I might be able to help you though.