so i have a streaming level named Maingame. and there is persitant level named Bomb. so in order to edit thing i generally open my Maingame level, but when i press the ‘save current’ button on top left corner of viewport, mapbuiltdata.uasset of maingame level get corrupt. before corruption it was 32mb, after getting corrupt it gets reduced to 1kb which is a clear sign of corruption. plus because of corruption unreal is not even loading that file. luckily because of this problem i am always keeping an updated back up of that file(which is not corrupted), so when it gets corrupt i replace it with my backup one before starting unreal. now what happens is that when unreal fails to load that file i lose all of that level’s light built and reflection data. so i require little help.
i am using version 4.14.3