FIXED IT! hi i had the exact same problem with the same map Soul Slum, and was able to fix it! I installed both UE4.23.1 and UE4.25.3. I was able to first open the map on UE 4.23.1 by first going into the textures like HARMze suggests doing and reducing their size. The same trick would not work in 4.25.3, so in 4.23.1, I would try different things to the map, and then “migrate” it to a 4.25 project and try to open it from there. So i literally started to remove elements from the map 1 by 1, and then saved and migrated the map to a 4.25 project. It kept crashing in the same way you described, UNTIL i tried deleting all the SphereReflectionCaptures via the World Outliner. Once i did that in 4.23.1 and migrated the map to my 4.25 project, i was able to load up that 4.25 project and open the map up successfully. let me know if that works for you.